diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index b6b1fdaff..168915be6 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -46,6 +46,7 @@
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
     <uses-permission android:name="android.permission.WRITE_SETTINGS"/>
     <uses-permission android:name="android.permission.NFC"/>
+    <uses-permission android:name="android.permission.WAKE_LOCK"/>
 
     <!-- Indicate that F-Droid may request root access (introduced by Koush's Superuser app)
          This permission is deprecated, but necessary for some old superuser
@@ -251,7 +252,10 @@
             </intent-filter>
         </receiver>
 
-        <service android:name=".UpdateService"/>
+        <service
+                android:name=".UpdateService"
+                android:permission="android.permission.BIND_JOB_SERVICE"
+                android:exported="false"/>
         <service
                 android:name=".UpdateJobService"
                 android:exported="false"
@@ -261,18 +265,26 @@
                 android:exported="false"/>
         <service
                 android:name=".installer.InstallerService"
+                android:permission="android.permission.BIND_JOB_SERVICE"
                 android:exported="false"/>
         <service
                 android:name=".CleanCacheService"
+                android:permission="android.permission.BIND_JOB_SERVICE"
+                android:exported="false"/>
+        <service
+                android:name=".CleanCacheJobService"
+                android:permission="android.permission.BIND_JOB_SERVICE"
                 android:exported="false"/>
         <service
                 android:name=".DeleteCacheService"
+                android:permission="android.permission.BIND_JOB_SERVICE"
                 android:exported="false"/>
         <service
                 android:name=".net.WifiStateChangeService"
                 android:exported="false"/>
         <service
                 android:name=".net.ConnectivityMonitorService"
+                android:permission="android.permission.BIND_JOB_SERVICE"
                 android:exported="false"/>
         <service android:name=".localrepo.SwapService"/>
         <service
@@ -286,6 +298,7 @@
                 android:exported="false"/>
         <service
                 android:name=".data.InstalledAppProviderService"
+                android:permission="android.permission.BIND_JOB_SERVICE"
                 android:exported="false"/>
         <service
                 android:name=".AppUpdateStatusService"
diff --git a/app/src/main/java/org/fdroid/fdroid/CleanCacheJobService.java b/app/src/main/java/org/fdroid/fdroid/CleanCacheJobService.java
new file mode 100644
index 000000000..bbf3d78f8
--- /dev/null
+++ b/app/src/main/java/org/fdroid/fdroid/CleanCacheJobService.java
@@ -0,0 +1,22 @@
+package org.fdroid.fdroid;
+
+import android.annotation.TargetApi;
+import android.app.job.JobParameters;
+import android.app.job.JobService;
+
+/**
+ * Shim to run {@link CleanCacheService} with {@link android.app.job.JobScheduler}
+ */
+@TargetApi(21)
+public class CleanCacheJobService extends JobService {
+    @Override
+    public boolean onStartJob(JobParameters jobParameters) {
+        CleanCacheService.start(this);
+        return false;
+    }
+
+    @Override
+    public boolean onStopJob(JobParameters jobParameters) {
+        return true;
+    }
+}
diff --git a/app/src/main/java/org/fdroid/fdroid/CleanCacheService.java b/app/src/main/java/org/fdroid/fdroid/CleanCacheService.java
index da887eb00..ebff5c465 100644
--- a/app/src/main/java/org/fdroid/fdroid/CleanCacheService.java
+++ b/app/src/main/java/org/fdroid/fdroid/CleanCacheService.java
@@ -1,13 +1,17 @@
 package org.fdroid.fdroid;
 
 import android.app.AlarmManager;
-import android.app.IntentService;
 import android.app.PendingIntent;
+import android.app.job.JobInfo;
+import android.app.job.JobScheduler;
+import android.content.ComponentName;
 import android.content.Context;
 import android.content.Intent;
 import android.os.Build;
 import android.os.Process;
 import android.os.SystemClock;
+import android.support.annotation.NonNull;
+import android.support.v4.app.JobIntentService;
 import org.apache.commons.io.FileUtils;
 import org.fdroid.fdroid.installer.ApkCache;
 
@@ -27,7 +31,10 @@ import java.util.concurrent.TimeUnit;
  * and newer.  On older Android, last modified time from {@link File#lastModified()}
  * is used.
  */
-public class CleanCacheService extends IntentService {
+public class CleanCacheService extends JobIntentService {
+    public static final String TAG = "CleanCacheService";
+
+    private static final int JOB_ID = 0x982374;
 
     /**
      * Schedule or cancel this service to update the app index, according to the
@@ -41,28 +48,36 @@ public class CleanCacheService extends IntentService {
             interval = keepTime;
         }
 
-        Intent intent = new Intent(context, CleanCacheService.class);
-        PendingIntent pending = PendingIntent.getService(context, 0, intent, 0);
+        if (Build.VERSION.SDK_INT < 21) {
+            Intent intent = new Intent(context, CleanCacheService.class);
+            PendingIntent pending = PendingIntent.getService(context, 0, intent, 0);
 
-        AlarmManager alarm = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
-        alarm.cancel(pending);
-        alarm.setInexactRepeating(AlarmManager.ELAPSED_REALTIME,
-                SystemClock.elapsedRealtime() + 5000, interval, pending);
+            AlarmManager alarm = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
+            alarm.cancel(pending);
+            alarm.setInexactRepeating(AlarmManager.ELAPSED_REALTIME,
+                    SystemClock.elapsedRealtime() + 5000, interval, pending);
+        } else {
+            Utils.debugLog(TAG, "Using android-21 JobScheduler for updates");
+            JobScheduler jobScheduler = (JobScheduler) context.getSystemService(Context.JOB_SCHEDULER_SERVICE);
+            ComponentName componentName = new ComponentName(context, CleanCacheJobService.class);
+            JobInfo.Builder builder = new JobInfo.Builder(JOB_ID, componentName)
+                    .setRequiresDeviceIdle(true)
+                    .setRequiresCharging(true)
+                    .setPeriodic(interval);
+            if (Build.VERSION.SDK_INT >= 26) {
+                builder.setRequiresBatteryNotLow(true);
+            }
+            jobScheduler.schedule(builder.build());
+
+        }
     }
 
     public static void start(Context context) {
-        context.startService(new Intent(context, CleanCacheService.class));
-    }
-
-    public CleanCacheService() {
-        super("CleanCacheService");
+        enqueueWork(context, CleanCacheService.class, JOB_ID, new Intent(context, CleanCacheService.class));
     }
 
     @Override
-    protected void onHandleIntent(Intent intent) {
-        if (intent == null) {
-            return;
-        }
+    protected void onHandleWork(@NonNull Intent intent) {
         Process.setThreadPriority(Process.THREAD_PRIORITY_LOWEST);
         deleteExpiredApksFromCache();
         deleteStrayIndexFiles();
diff --git a/app/src/main/java/org/fdroid/fdroid/DeleteCacheService.java b/app/src/main/java/org/fdroid/fdroid/DeleteCacheService.java
index 8832d1b1a..b526cc2ed 100644
--- a/app/src/main/java/org/fdroid/fdroid/DeleteCacheService.java
+++ b/app/src/main/java/org/fdroid/fdroid/DeleteCacheService.java
@@ -1,9 +1,10 @@
 package org.fdroid.fdroid;
 
-import android.app.IntentService;
 import android.content.Context;
 import android.content.Intent;
 import android.os.Process;
+import android.support.annotation.NonNull;
+import android.support.v4.app.JobIntentService;
 import android.support.v4.content.ContextCompat;
 import android.util.Log;
 import org.apache.commons.io.FileUtils;
@@ -11,25 +12,18 @@ import org.apache.commons.io.FileUtils;
 import java.io.File;
 
 /**
- * An {@link IntentService} subclass for deleting the full cache for this app.
+ * An {@link JobIntentService} subclass for deleting the full cache for this app.
  */
-public class DeleteCacheService extends IntentService {
+public class DeleteCacheService extends JobIntentService {
     public static final String TAG = "DeleteCacheService";
 
-    public DeleteCacheService() {
-        super("DeleteCacheService");
-    }
-
     public static void deleteAll(Context context) {
         Intent intent = new Intent(context, DeleteCacheService.class);
-        context.startService(intent);
+        enqueueWork(context, DeleteCacheService.class, 0x523432, intent);
     }
 
     @Override
-    protected void onHandleIntent(Intent intent) {
-        if (intent == null) {
-            return;
-        }
+    protected void onHandleWork(@NonNull Intent intent) {
         Process.setThreadPriority(Process.THREAD_PRIORITY_LOWEST);
         Log.w(TAG, "Deleting all cached contents!");
         try {
diff --git a/app/src/main/java/org/fdroid/fdroid/UpdateJobService.java b/app/src/main/java/org/fdroid/fdroid/UpdateJobService.java
index 73561ce19..6911584b4 100644
--- a/app/src/main/java/org/fdroid/fdroid/UpdateJobService.java
+++ b/app/src/main/java/org/fdroid/fdroid/UpdateJobService.java
@@ -3,15 +3,10 @@ package org.fdroid.fdroid;
 import android.annotation.TargetApi;
 import android.app.job.JobParameters;
 import android.app.job.JobService;
-import android.content.Intent;
 
 /**
  * Interface between the new {@link android.app.job.JobScheduler} API and
- * our old {@link UpdateService}, which is based on {@link android.app.IntentService}.
- * This does not do things the way it should, e.g. stopping the job on
- * {@link #onStopJob(JobParameters)} and properly reporting
- * {@link #jobFinished(JobParameters, boolean)}, but this at least provides
- * the nice early triggering when there is good power/wifi available.
+ * {@link UpdateService}, which is based on {@link android.support.v4.app.JobIntentService}.
  *
  * @see <a href="https://developer.android.com/about/versions/android-5.0.html#Power">Project Volta: Scheduling jobs</a>
  */
@@ -19,25 +14,13 @@ import android.content.Intent;
 public class UpdateJobService extends JobService {
     @Override
     public boolean onStartJob(final JobParameters params) {
-        new Thread() {
-            @Override
-            public void run() {
-                // faking the actually run time
-                try {
-                    startService(new Intent(UpdateJobService.this, UpdateService.class));
-                    Thread.sleep(2000);
-                } catch (InterruptedException e) {
-                    // ignored
-                } finally {
-                    jobFinished(params, false);
-                }
-            }
-        }.start();
-        return true;
+        UpdateService.updateNow(this);
+        return false;
     }
 
     @Override
     public boolean onStopJob(JobParameters params) {
-        return false;
+        // TODO this should gracefully stop UpdateService
+        return true;
     }
 }
diff --git a/app/src/main/java/org/fdroid/fdroid/UpdateService.java b/app/src/main/java/org/fdroid/fdroid/UpdateService.java
index 563bfd405..7e431430e 100644
--- a/app/src/main/java/org/fdroid/fdroid/UpdateService.java
+++ b/app/src/main/java/org/fdroid/fdroid/UpdateService.java
@@ -30,12 +30,15 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.content.SharedPreferences;
+import android.net.Uri;
 import android.os.AsyncTask;
 import android.os.Build;
 import android.os.Handler;
 import android.os.Looper;
 import android.os.Process;
 import android.os.SystemClock;
+import android.support.annotation.NonNull;
+import android.support.v4.app.JobIntentService;
 import android.support.v4.app.NotificationCompat;
 import android.support.v4.content.LocalBroadcastManager;
 import android.support.v7.preference.PreferenceManager;
@@ -59,7 +62,7 @@ import java.lang.ref.WeakReference;
 import java.util.ArrayList;
 import java.util.List;
 
-public class UpdateService extends IntentService {
+public class UpdateService extends JobIntentService {
 
     private static final String TAG = "UpdateService";
 
@@ -68,7 +71,6 @@ public class UpdateService extends IntentService {
     public static final String EXTRA_MESSAGE = "msg";
     public static final String EXTRA_REPO_ERRORS = "repoErrors";
     public static final String EXTRA_STATUS_CODE = "status";
-    public static final String EXTRA_ADDRESS = "address";
     public static final String EXTRA_MANUAL_UPDATE = "manualUpdate";
     public static final String EXTRA_FORCED_UPDATE = "forcedUpdate";
     public static final String EXTRA_PROGRESS = "progress";
@@ -81,6 +83,7 @@ public class UpdateService extends IntentService {
     public static final int STATUS_INFO = 5;
 
     private static final String STATE_LAST_UPDATED = "lastUpdateCheck";
+    private static final int JOB_ID = 0xfedcba;
 
     private static final int NOTIFY_ID_UPDATING = 0;
 
@@ -92,10 +95,6 @@ public class UpdateService extends IntentService {
 
     private static boolean updating;
 
-    public UpdateService() {
-        super("UpdateService");
-    }
-
     public static void updateNow(Context context) {
         updateRepoNow(context, null);
     }
@@ -104,9 +103,9 @@ public class UpdateService extends IntentService {
         Intent intent = new Intent(context, UpdateService.class);
         intent.putExtra(EXTRA_MANUAL_UPDATE, true);
         if (!TextUtils.isEmpty(address)) {
-            intent.putExtra(EXTRA_ADDRESS, address);
+            intent.setData(Uri.parse(address));
         }
-        context.startService(intent);
+        enqueueWork(context, intent);
     }
 
     /**
@@ -117,7 +116,16 @@ public class UpdateService extends IntentService {
     public static void forceUpdateRepo(Context context) {
         Intent intent = new Intent(context, UpdateService.class);
         intent.putExtra(EXTRA_FORCED_UPDATE, true);
-        context.startService(intent);
+        enqueueWork(context, intent);
+    }
+
+    /**
+     * Add work to the queue for processing now
+     *
+     * @see JobIntentService#enqueueWork(Context, Class, int, Intent)
+     */
+    private static void enqueueWork(Context context, @NonNull Intent intent) {
+        enqueueWork(context, UpdateService.class, JOB_ID, intent);
     }
 
     /**
@@ -150,7 +158,7 @@ public class UpdateService extends IntentService {
             Utils.debugLog(TAG, "Using android-21 JobScheduler for updates");
             JobScheduler jobScheduler = (JobScheduler) context.getSystemService(Context.JOB_SCHEDULER_SERVICE);
             ComponentName componentName = new ComponentName(context, UpdateJobService.class);
-            JobInfo.Builder builder = new JobInfo.Builder(0xfedcba, componentName)
+            JobInfo.Builder builder = new JobInfo.Builder(JOB_ID, componentName)
                     .setRequiresDeviceIdle(true)
                     .setPeriodic(interval);
             if (Build.VERSION.SDK_INT >= 26) {
@@ -368,18 +376,13 @@ public class UpdateService extends IntentService {
     }
 
     @Override
-    protected void onHandleIntent(Intent intent) {
+    protected void onHandleWork(@NonNull Intent intent) {
         Process.setThreadPriority(Process.THREAD_PRIORITY_LOWEST);
 
         final long startTime = System.currentTimeMillis();
-        boolean manualUpdate = false;
-        boolean forcedUpdate = false;
-        String address = null;
-        if (intent != null) {
-            address = intent.getStringExtra(EXTRA_ADDRESS); // TODO switch to Intent.setData()
-            manualUpdate = intent.getBooleanExtra(EXTRA_MANUAL_UPDATE, false);
-            forcedUpdate = intent.getBooleanExtra(EXTRA_FORCED_UPDATE, false);
-        }
+        boolean manualUpdate = intent.getBooleanExtra(EXTRA_MANUAL_UPDATE, false);
+        boolean forcedUpdate = intent.getBooleanExtra(EXTRA_FORCED_UPDATE, false);
+        String address = intent.getDataString();
 
         try {
             final Preferences fdroidPrefs = Preferences.get();
diff --git a/app/src/main/java/org/fdroid/fdroid/Utils.java b/app/src/main/java/org/fdroid/fdroid/Utils.java
index 73944d1fa..0f5c938f4 100644
--- a/app/src/main/java/org/fdroid/fdroid/Utils.java
+++ b/app/src/main/java/org/fdroid/fdroid/Utils.java
@@ -492,6 +492,7 @@ public final class Utils {
      * probably warranted. See https://www.gitlab.com/fdroid/fdroidclient/issues/855
      * for more detail.
      */
+    @Nullable
     public static String getBinaryHash(File apk, String algo) {
         FileInputStream fis = null;
         try {
@@ -514,12 +515,12 @@ public final class Utils {
             } else if (message.contains(" ENOENT ")) {
                 Utils.debugLog(TAG, apk + " vanished: " + message);
             }
-            throw new IllegalArgumentException(e);
         } catch (NoSuchAlgorithmException e) {
             throw new IllegalArgumentException(e);
         } finally {
             closeQuietly(fis);
         }
+        return null;
     }
 
     /**
diff --git a/app/src/main/java/org/fdroid/fdroid/data/Apk.java b/app/src/main/java/org/fdroid/fdroid/data/Apk.java
index 0c14c1fd5..2618edd94 100644
--- a/app/src/main/java/org/fdroid/fdroid/data/Apk.java
+++ b/app/src/main/java/org/fdroid/fdroid/data/Apk.java
@@ -70,6 +70,7 @@ public class Apk extends ValueObject implements Comparable<Apk>, Parcelable {
     public String versionName;
     public int versionCode;
     public int size; // Size in bytes - 0 means we don't know!
+    @NonNull
     public String hash; // checksum of the APK, in lowercase hex
     public String hashType;
     public int minSdkVersion = SDK_VERSION_MIN_VALUE; // 0 if unknown
@@ -358,7 +359,7 @@ public class Apk extends ValueObject implements Comparable<Apk>, Parcelable {
 
     @Override
     @TargetApi(19)
-    public int compareTo(Apk apk) {
+    public int compareTo(@NonNull Apk apk) {
         if (Build.VERSION.SDK_INT < 19) {
             return Integer.valueOf(versionCode).compareTo(apk.versionCode);
         }
diff --git a/app/src/main/java/org/fdroid/fdroid/data/ApkProvider.java b/app/src/main/java/org/fdroid/fdroid/data/ApkProvider.java
index f132c6c4d..3a1ea2cf1 100644
--- a/app/src/main/java/org/fdroid/fdroid/data/ApkProvider.java
+++ b/app/src/main/java/org/fdroid/fdroid/data/ApkProvider.java
@@ -9,7 +9,6 @@ import android.net.Uri;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.util.Log;
-
 import org.fdroid.fdroid.Utils;
 import org.fdroid.fdroid.data.Schema.AntiFeatureTable;
 import org.fdroid.fdroid.data.Schema.ApkAntiFeatureJoinTable;
@@ -20,13 +19,13 @@ import org.fdroid.fdroid.data.Schema.PackageTable;
 import org.fdroid.fdroid.data.Schema.RepoTable;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
-@SuppressWarnings("LineLength")
 public class ApkProvider extends FDroidProvider {
 
     private static final String TAG = "ApkProvider";
@@ -41,7 +40,8 @@ public class ApkProvider extends FDroidProvider {
 
     public static final class Helper {
 
-        private Helper() { }
+        private Helper() {
+        }
 
         public static void update(Context context, Apk apk) {
             ContentResolver resolver = context.getContentResolver();
@@ -83,19 +83,21 @@ public class ApkProvider extends FDroidProvider {
         /**
          * Find an app which is closest to the version code suggested by the server, with some caveates:
          * <ul>
-         *     <li>If installed, limit to apks signed by the same signer as the installed apk.</li>
-         *     <li>Otherwise, limit to apks signed by the "preferred" signer (see {@link App#preferredSigner}).</li>
+         * <li>If installed, limit to apks signed by the same signer as the installed apk.</li>
+         * <li>Otherwise, limit to apks signed by the "preferred" signer (see {@link App#preferredSigner}).</li>
          * </ul>
          */
         public static Apk findSuggestedApk(Context context, App app) {
-            return findApkFromAnyRepo(context, app.packageName, app.suggestedVersionCode, app.getMostAppropriateSignature());
+            return findApkFromAnyRepo(context, app.packageName, app.suggestedVersionCode,
+                    app.getMostAppropriateSignature());
         }
 
         public static Apk findApkFromAnyRepo(Context context, String packageName, int versionCode) {
             return findApkFromAnyRepo(context, packageName, versionCode, null, Cols.ALL);
         }
 
-        public static Apk findApkFromAnyRepo(Context context, String packageName, int versionCode, String signature) {
+        public static Apk findApkFromAnyRepo(Context context, String packageName, int versionCode,
+                                             String signature) {
             return findApkFromAnyRepo(context, packageName, versionCode, signature, Cols.ALL);
         }
 
@@ -162,6 +164,9 @@ public class ApkProvider extends FDroidProvider {
 
         @NonNull
         public static List<Apk> findApksByHash(Context context, String apkHash) {
+            if (apkHash == null) {
+                return Collections.emptyList();
+            }
             ContentResolver resolver = context.getContentResolver();
             final Uri uri = getContentUri();
             String selection = " apk." + Cols.HASH + " = ? ";
@@ -185,7 +190,7 @@ public class ApkProvider extends FDroidProvider {
     protected static final String PATH_REPO_APP = "repo-app";
     private static final String PATH_APKS = "apks";
     private static final String PATH_APP = "app";
-    private static final String PATH_REPO      = "repo";
+    private static final String PATH_REPO = "repo";
     private static final String PATH_APK_ROW_ID = "apk-rowId";
 
     private static final UriMatcher MATCHER = new UriMatcher(-1);
@@ -226,27 +231,27 @@ public class ApkProvider extends FDroidProvider {
 
     public static Uri getAppUri(String packageName) {
         return getContentUri()
-            .buildUpon()
-            .appendPath(PATH_APP)
-            .appendPath(packageName)
-            .build();
+                .buildUpon()
+                .appendPath(PATH_APP)
+                .appendPath(packageName)
+                .build();
     }
 
     public static Uri getRepoUri(long repoId) {
         return getContentUri()
-            .buildUpon()
-            .appendPath(PATH_REPO)
-            .appendPath(Long.toString(repoId))
-            .build();
+                .buildUpon()
+                .appendPath(PATH_REPO)
+                .appendPath(Long.toString(repoId))
+                .build();
     }
 
     public static Uri getRepoUri(long repoId, String packageName) {
         return getContentUri()
-            .buildUpon()
-            .appendPath(PATH_REPO_APP)
-            .appendPath(Long.toString(repoId))
-            .appendPath(packageName)
-            .build();
+                .buildUpon()
+                .appendPath(PATH_REPO_APP)
+                .appendPath(Long.toString(repoId))
+                .appendPath(packageName)
+                .build();
     }
 
     public static Uri getApkFromAnyRepoUri(Apk apk) {
@@ -296,10 +301,13 @@ public class ApkProvider extends FDroidProvider {
         private boolean antiFeaturesRequested;
 
         /**
-         * If the query includes anti features, then we group by apk id. This is because joining onto the anti-features
-         * table will result in multiple result rows for each apk (potentially), so we will GROUP_CONCAT each of the
-         * anti features into a single comma separated list for each apk. If we are _not_ including anti features, then
-         * don't group by apk, because when doing a COUNT(*) this will result in the wrong result.
+         * If the query includes anti features, then we group by apk id. This
+         * is because joining onto the anti-features table will result in
+         * multiple result rows for each apk (potentially), so we will
+         * {@code GROUP_CONCAT} each of the anti-features into a single comma-
+         * separated list for each apk. If we are _not_ including anti-
+         * features, then don't group by apk, because when doing a COUNT(*)
+         * this will result in the wrong result.
          */
         @Override
         protected String groupBy() {
@@ -313,8 +321,8 @@ public class ApkProvider extends FDroidProvider {
             final String pkg = PackageTable.NAME;
 
             return apk + " AS apk " +
-                " LEFT JOIN " + app + " AS app ON (app." + AppMetadataTable.Cols.ROW_ID + " = apk." + Cols.APP_ID + ")" +
-                " LEFT JOIN " + pkg + " AS pkg ON (pkg." + PackageTable.Cols.ROW_ID + " = app." + AppMetadataTable.Cols.PACKAGE_ID + ")";
+                    " LEFT JOIN " + app + " AS app ON (app." + AppMetadataTable.Cols.ROW_ID + " = apk." + Cols.APP_ID + ")" + // NOPMD NOCHECKSTYLE LineLength
+                    " LEFT JOIN " + pkg + " AS pkg ON (pkg." + PackageTable.Cols.ROW_ID + " = app." + AppMetadataTable.Cols.PACKAGE_ID + ")"; // NOPMD NOCHECKSTYLE LineLength
         }
 
         @Override
@@ -357,9 +365,11 @@ public class ApkProvider extends FDroidProvider {
                     "apk." + Cols.ROW_ID + " = " + apkAntiFeature + "." + ApkAntiFeatureJoinTable.Cols.APK_ID);
 
             leftJoin(AntiFeatureTable.NAME, antiFeature,
-                    apkAntiFeature + "." + ApkAntiFeatureJoinTable.Cols.ANTI_FEATURE_ID + " = " + antiFeature + "." + AntiFeatureTable.Cols.ROW_ID);
+                    apkAntiFeature + "." + ApkAntiFeatureJoinTable.Cols.ANTI_FEATURE_ID + " = "
+                            + antiFeature + "." + AntiFeatureTable.Cols.ROW_ID);
 
-            appendField("group_concat(" + antiFeature + "." + AntiFeatureTable.Cols.NAME + ") as " + Cols.AntiFeatures.ANTI_FEATURES);
+            appendField("group_concat(" + antiFeature + "." + AntiFeatureTable.Cols.NAME + ") as "
+                    + Cols.AntiFeatures.ANTI_FEATURES);
         }
     }
 
@@ -378,11 +388,11 @@ public class ApkProvider extends FDroidProvider {
 
         String selection =
                 alias + Cols.VERSION_CODE + " = ? AND " +
-                alias + Cols.APP_ID + " IN (" + getMetadataIdFromPackageNameQuery() + ")";
+                        alias + Cols.APP_ID + " IN (" + getMetadataIdFromPackageNameQuery() + ")";
 
         List<String> pathSegments = uri.getPathSegments();
         List<String> args = new ArrayList<>(3);
-        args.add(pathSegments.get(1)); // First (0th) path segment is the word "apk" and we are not interested in it.
+        args.add(pathSegments.get(1)); // 0th path segment is the word "apk" and we are not interested in it.
         args.add(pathSegments.get(2));
 
         if (pathSegments.size() >= 4) {
@@ -438,8 +448,8 @@ public class ApkProvider extends FDroidProvider {
         final String[] apkDetails = apkKeys.split(",");
         if (apkDetails.length > MAX_APKS_TO_QUERY) {
             throw new IllegalArgumentException(
-                "Cannot query more than " + MAX_APKS_TO_QUERY + ". " +
-                "You tried to query " + apkDetails.length);
+                    "Cannot query more than " + MAX_APKS_TO_QUERY + ". " +
+                            "You tried to query " + apkDetails.length);
         }
         String alias = includeAlias ? "apk." : "";
         final String[] args = new String[apkDetails.length * 2];
@@ -569,7 +579,9 @@ public class ApkProvider extends FDroidProvider {
     }
 
     protected void ensureAntiFeatures(String[] antiFeatures, long apkId) {
-        db().delete(getApkAntiFeatureJoinTableName(), ApkAntiFeatureJoinTable.Cols.APK_ID + " = ?", new String[] {Long.toString(apkId)});
+        db().delete(getApkAntiFeatureJoinTableName(),
+                ApkAntiFeatureJoinTable.Cols.APK_ID + " = ?",
+                new String[]{Long.toString(apkId)});
         if (antiFeatures != null) {
             Set<String> antiFeatureSet = new HashSet<>();
             for (String antiFeatureName : antiFeatures) {
@@ -594,7 +606,8 @@ public class ApkProvider extends FDroidProvider {
 
     protected long ensureAntiFeature(String antiFeatureName) {
         long antiFeatureId = 0;
-        Cursor cursor = db().query(AntiFeatureTable.NAME, new String[] {AntiFeatureTable.Cols.ROW_ID}, AntiFeatureTable.Cols.NAME + " = ?", new String[]{antiFeatureName}, null, null, null);
+        Cursor cursor = db().query(AntiFeatureTable.NAME, new String[]{AntiFeatureTable.Cols.ROW_ID},
+                AntiFeatureTable.Cols.NAME + " = ?", new String[]{antiFeatureName}, null, null, null);
         if (cursor != null) {
             if (cursor.getCount() > 0) {
                 cursor.moveToFirst();
diff --git a/app/src/main/java/org/fdroid/fdroid/data/App.java b/app/src/main/java/org/fdroid/fdroid/data/App.java
index c89b92185..33b6b5ee4 100644
--- a/app/src/main/java/org/fdroid/fdroid/data/App.java
+++ b/app/src/main/java/org/fdroid/fdroid/data/App.java
@@ -369,15 +369,33 @@ public class App extends ValueObject implements Comparable<App>, Parcelable {
 
     /**
      * Instantiate from a locally installed package.
+     * <p>
+     * Initializes an {@link App} instances from an APK file. Since the file
+     * could in the cache, and files can disappear from the cache at any time,
+     * this needs to be quite defensive ensuring that {@code apkFile} still
+     * exists.
      */
-    public App(Context context, PackageManager pm, String packageName)
+    @Nullable
+    public static App getInstance(Context context, PackageManager pm, String packageName)
             throws CertificateEncodingException, IOException, PackageManager.NameNotFoundException {
-
+        App app = new App();
         PackageInfo packageInfo = pm.getPackageInfo(packageName, PackageManager.GET_PERMISSIONS);
-        setFromPackageInfo(pm, packageInfo);
-        this.installedApk = new Apk();
         SanitizedFile apkFile = SanitizedFile.knownSanitized(packageInfo.applicationInfo.publicSourceDir);
-        initApkFromApkFile(context, this.installedApk, packageInfo, apkFile);
+        if (apkFile.canRead()) {
+            String hashType = "SHA-256";
+            String hash = Utils.getBinaryHash(apkFile, hashType);
+            if (TextUtils.isEmpty(hash)) {
+                return null;
+            }
+            app.installedApk.hashType = hashType;
+            app.installedApk.hash = hash;
+            app.installedApk.sig = Utils.getPackageSig(packageInfo);
+        }
+
+        app.setFromPackageInfo(pm, packageInfo);
+        app.installedApk = new Apk();
+        app.initInstalledApk(context, app.installedApk, packageInfo, apkFile);
+        return app;
     }
 
     /**
@@ -704,22 +722,6 @@ public class App extends ValueObject implements Comparable<App>, Parcelable {
         this.compatible = true;
     }
 
-    /**
-     * Initializes an {@link App} instances from an APK file. Since the file
-     * could in the cache, and files can disappear from the cache at any time,
-     * this needs to be quite defensive ensuring that {@code apkFile} still
-     * exists.
-     */
-    private void initApkFromApkFile(Context context, Apk apk, PackageInfo packageInfo, SanitizedFile apkFile)
-            throws IOException, CertificateEncodingException {
-        if (apkFile.canRead()) {
-            apk.hashType = "sha256";
-            apk.hash = Utils.getBinaryHash(apkFile, apk.hashType);
-            apk.sig = Utils.getPackageSig(packageInfo);
-        }
-        initInstalledApk(context, apk, packageInfo, apkFile);
-    }
-
     public static void initInstalledObbFiles(Apk apk) {
         File obbdir = getObbDir(apk.packageName);
         FileFilter filter = new RegexFileFilter("(main|patch)\\.[0-9-][0-9]*\\." + apk.packageName + "\\.obb");
@@ -743,6 +745,7 @@ public class App extends ValueObject implements Comparable<App>, Parcelable {
         }
     }
 
+    @SuppressWarnings("EmptyForIteratorPad")
     private void initInstalledApk(Context context, Apk apk, PackageInfo packageInfo, SanitizedFile apkFile)
             throws IOException, CertificateEncodingException {
         apk.compatible = true;
@@ -775,7 +778,7 @@ public class App extends ValueObject implements Comparable<App>, Parcelable {
         JarFile apkJar = new JarFile(apkFile);
         HashSet<String> abis = new HashSet<>(3);
         Pattern pattern = Pattern.compile("^lib/([a-z0-9-]+)/.*");
-        for (Enumeration<JarEntry> jarEntries = apkJar.entries(); jarEntries.hasMoreElements();) {
+        for (Enumeration<JarEntry> jarEntries = apkJar.entries(); jarEntries.hasMoreElements(); ) {
             JarEntry jarEntry = jarEntries.nextElement();
             Matcher matcher = pattern.matcher(jarEntry.getName());
             if (matcher.matches()) {
diff --git a/app/src/main/java/org/fdroid/fdroid/data/InstalledAppProviderService.java b/app/src/main/java/org/fdroid/fdroid/data/InstalledAppProviderService.java
index 9548ca057..0084c5e13 100644
--- a/app/src/main/java/org/fdroid/fdroid/data/InstalledAppProviderService.java
+++ b/app/src/main/java/org/fdroid/fdroid/data/InstalledAppProviderService.java
@@ -1,6 +1,5 @@
 package org.fdroid.fdroid.data;
 
-import android.app.IntentService;
 import android.content.ContentValues;
 import android.content.Context;
 import android.content.Intent;
@@ -8,7 +7,9 @@ import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
 import android.net.Uri;
 import android.os.Process;
+import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
+import android.support.v4.app.JobIntentService;
 import android.util.Log;
 import org.acra.ACRA;
 import org.fdroid.fdroid.AppUpdateStatusManager;
@@ -40,7 +41,7 @@ import java.util.concurrent.TimeUnit;
  * of this stuff.
  */
 @SuppressWarnings("LineLength")
-public class InstalledAppProviderService extends IntentService {
+public class InstalledAppProviderService extends JobIntentService {
     private static final String TAG = "InstalledAppProviderSer";
 
     private static final String ACTION_INSERT = "org.fdroid.fdroid.data.action.INSERT";
@@ -56,10 +57,6 @@ public class InstalledAppProviderService extends IntentService {
      */
     private PublishSubject<String> packageChangeNotifier;
 
-    public InstalledAppProviderService() {
-        super("InstalledAppProviderService");
-    }
-
     @Override
     public void onCreate() {
         super.onCreate();
@@ -121,7 +118,7 @@ public class InstalledAppProviderService extends IntentService {
         intent.setAction(ACTION_INSERT);
         intent.setData(uri);
         intent.putExtra(EXTRA_PACKAGE_INFO, packageInfo);
-        context.startService(intent);
+        enqueueWork(context, intent);
     }
 
     /**
@@ -138,7 +135,11 @@ public class InstalledAppProviderService extends IntentService {
         Intent intent = new Intent(context, InstalledAppProviderService.class);
         intent.setAction(ACTION_DELETE);
         intent.setData(uri);
-        context.startService(intent);
+        enqueueWork(context, intent);
+    }
+
+    private static void enqueueWork(Context context, Intent intent) {
+        enqueueWork(context, InstalledAppProviderService.class, 0x192834, intent);
     }
 
     /**
@@ -153,7 +154,7 @@ public class InstalledAppProviderService extends IntentService {
      * The installed app cache could get out of sync, e.g. if F-Droid crashed/ or
      * ran out of battery half way through responding to {@link Intent#ACTION_PACKAGE_ADDED}.
      * This method returns immediately, and will continue to work in an
-     * {@link IntentService}.  It doesn't really matter where we put this in the
+     * {@link JobIntentService}.  It doesn't really matter where we put this in the
      * bootstrap process, because it runs in its own thread, at the lowest priority:
      * {@link Process#THREAD_PRIORITY_LOWEST}.
      * <p>
@@ -218,11 +219,8 @@ public class InstalledAppProviderService extends IntentService {
     }
 
     @Override
-    protected void onHandleIntent(Intent intent) {
+    protected void onHandleWork(@NonNull Intent intent) {
         Process.setThreadPriority(Process.THREAD_PRIORITY_LOWEST);
-        if (intent == null) {
-            return;
-        }
 
         String packageName = intent.getData().getSchemeSpecificPart();
         final String action = intent.getAction();
diff --git a/app/src/main/java/org/fdroid/fdroid/installer/DefaultInstaller.java b/app/src/main/java/org/fdroid/fdroid/installer/DefaultInstaller.java
index 222256377..b806d5724 100644
--- a/app/src/main/java/org/fdroid/fdroid/installer/DefaultInstaller.java
+++ b/app/src/main/java/org/fdroid/fdroid/installer/DefaultInstaller.java
@@ -24,6 +24,7 @@ import android.app.PendingIntent;
 import android.content.Context;
 import android.content.Intent;
 import android.net.Uri;
+import android.support.annotation.NonNull;
 import org.fdroid.fdroid.data.Apk;
 
 /**
@@ -37,7 +38,7 @@ public class DefaultInstaller extends Installer {
 
     public static final String TAG = "DefaultInstaller";
 
-    DefaultInstaller(Context context, Apk apk) {
+    DefaultInstaller(Context context, @NonNull Apk apk) {
         super(context, apk);
     }
 
diff --git a/app/src/main/java/org/fdroid/fdroid/installer/ExtensionInstaller.java b/app/src/main/java/org/fdroid/fdroid/installer/ExtensionInstaller.java
index 8b710e00a..647ed89af 100644
--- a/app/src/main/java/org/fdroid/fdroid/installer/ExtensionInstaller.java
+++ b/app/src/main/java/org/fdroid/fdroid/installer/ExtensionInstaller.java
@@ -24,6 +24,7 @@ import android.app.PendingIntent;
 import android.content.Context;
 import android.content.Intent;
 import android.net.Uri;
+import android.support.annotation.NonNull;
 import org.fdroid.fdroid.BuildConfig;
 import org.fdroid.fdroid.data.Apk;
 import org.fdroid.fdroid.privileged.install.InstallExtensionDialogActivity;
@@ -44,7 +45,7 @@ import java.io.File;
 @Deprecated
 public class ExtensionInstaller extends Installer {
 
-    ExtensionInstaller(Context context, Apk apk) {
+    ExtensionInstaller(Context context, @NonNull Apk apk) {
         super(context, apk);
     }
 
diff --git a/app/src/main/java/org/fdroid/fdroid/installer/FileInstaller.java b/app/src/main/java/org/fdroid/fdroid/installer/FileInstaller.java
index 9356159aa..aa7d41d48 100644
--- a/app/src/main/java/org/fdroid/fdroid/installer/FileInstaller.java
+++ b/app/src/main/java/org/fdroid/fdroid/installer/FileInstaller.java
@@ -24,11 +24,12 @@ import android.content.Context;
 import android.content.Intent;
 import android.net.Uri;
 
+import android.support.annotation.NonNull;
 import org.fdroid.fdroid.data.Apk;
 
 public class FileInstaller extends Installer {
 
-    public FileInstaller(Context context, Apk apk) {
+    public FileInstaller(Context context, @NonNull Apk apk) {
         super(context, apk);
     }
 
diff --git a/app/src/main/java/org/fdroid/fdroid/installer/Installer.java b/app/src/main/java/org/fdroid/fdroid/installer/Installer.java
index bb0735b4b..38268e983 100644
--- a/app/src/main/java/org/fdroid/fdroid/installer/Installer.java
+++ b/app/src/main/java/org/fdroid/fdroid/installer/Installer.java
@@ -28,6 +28,7 @@ import android.content.pm.PackageManager;
 import android.net.Uri;
 import android.os.Build;
 import android.os.PatternMatcher;
+import android.support.annotation.NonNull;
 import android.support.v4.content.LocalBroadcastManager;
 import android.text.TextUtils;
 import org.fdroid.fdroid.Utils;
@@ -77,7 +78,7 @@ public abstract class Installer {
      * @param apk must be included so that all the phases of the install process
      *            can get all the data about the app, even after F-Droid was killed
      */
-    Installer(Context context, Apk apk) {
+    Installer(Context context, @NonNull Apk apk) {
         this.context = context;
         this.apk = apk;
     }
@@ -144,9 +145,10 @@ public abstract class Installer {
         }
 
         PackageManager pm = context.getPackageManager();
-        if (Build.VERSION.SDK_INT >= 24 && (
-                pm.getInstallerPackageName(apk.packageName).equals("com.android.packageinstaller")
-                        || pm.getInstallerPackageName(apk.packageName).equals("com.google.android.packageinstaller"))) {
+        String installerPackageName = pm.getInstallerPackageName(apk.packageName);
+        if (Build.VERSION.SDK_INT >= 24 &&
+                ("com.android.packageinstaller".equals(installerPackageName)
+                        || "com.google.android.packageinstaller".equals(installerPackageName))) {
             Utils.debugLog(TAG, "Falling back to default installer for uninstall");
             Intent intent = new Intent(context, DefaultInstallerActivity.class);
             intent.setAction(DefaultInstallerActivity.ACTION_UNINSTALL_PACKAGE);
diff --git a/app/src/main/java/org/fdroid/fdroid/installer/InstallerFactory.java b/app/src/main/java/org/fdroid/fdroid/installer/InstallerFactory.java
index 072b1de74..12acd9079 100644
--- a/app/src/main/java/org/fdroid/fdroid/installer/InstallerFactory.java
+++ b/app/src/main/java/org/fdroid/fdroid/installer/InstallerFactory.java
@@ -21,8 +21,8 @@
 package org.fdroid.fdroid.installer;
 
 import android.content.Context;
+import android.support.annotation.NonNull;
 import android.text.TextUtils;
-
 import org.fdroid.fdroid.Utils;
 import org.fdroid.fdroid.data.Apk;
 
@@ -39,12 +39,11 @@ public class InstallerFactory {
      * @param apk     to be installed, always required.
      * @return instance of an Installer
      */
-    public static Installer create(Context context, Apk apk) {
-        if (apk == null || TextUtils.isEmpty(apk.packageName)) {
+    public static Installer create(Context context, @NonNull Apk apk) {
+        if (TextUtils.isEmpty(apk.packageName)) {
             throw new IllegalArgumentException("Apk.packageName must not be empty: " + apk);
         }
 
-
         Installer installer;
         if (!apk.isApk()) {
             Utils.debugLog(TAG, "Using FileInstaller for non-apk file");
diff --git a/app/src/main/java/org/fdroid/fdroid/installer/InstallerService.java b/app/src/main/java/org/fdroid/fdroid/installer/InstallerService.java
index da2736b05..140665c58 100644
--- a/app/src/main/java/org/fdroid/fdroid/installer/InstallerService.java
+++ b/app/src/main/java/org/fdroid/fdroid/installer/InstallerService.java
@@ -20,11 +20,11 @@
 
 package org.fdroid.fdroid.installer;
 
-import android.app.IntentService;
 import android.content.Context;
 import android.content.Intent;
 import android.net.Uri;
-
+import android.support.annotation.NonNull;
+import android.support.v4.app.JobIntentService;
 import org.apache.commons.io.FileUtils;
 import org.apache.commons.io.filefilter.WildcardFileFilter;
 import org.fdroid.fdroid.Utils;
@@ -37,11 +37,13 @@ import java.io.FileFilter;
  * This service handles the install process of apk files and
  * uninstall process of apps.
  * <p>
- * This service is based on an IntentService because:
- * - no parallel installs/uninstalls should be allowed,
- * i.e., runs sequentially
- * - no cancel operation is needed. Cancelling an installation
- * would be the same as starting uninstall afterwards
+ * This service is based on an JobIntentService because:
+ * <ul>
+ * <li>no parallel installs/uninstalls should be allowed,
+ * i.e., runs sequentially</li>
+ * <li>no cancel operation is needed. Cancelling an installation
+ * would be the same as starting uninstall afterwards</li>
+ * </ul>
  * <p>
  * The download URL is only used as the unique ID that represents this
  * particular apk throughout the whole install process in
@@ -52,23 +54,15 @@ import java.io.FileFilter;
  * <a href="https://developer.android.com/google/play/expansion-files.html">
  * APK Expansion Files</a> spec.
  */
-public class InstallerService extends IntentService {
+public class InstallerService extends JobIntentService {
     public static final String TAG = "InstallerService";
 
     private static final String ACTION_INSTALL = "org.fdroid.fdroid.installer.InstallerService.action.INSTALL";
     private static final String ACTION_UNINSTALL = "org.fdroid.fdroid.installer.InstallerService.action.UNINSTALL";
 
-    public InstallerService() {
-        super("InstallerService");
-    }
-
     @Override
-    protected void onHandleIntent(Intent intent) {
+    protected void onHandleWork(@NonNull Intent intent) {
         final Apk apk = intent.getParcelableExtra(Installer.EXTRA_APK);
-        if (apk == null) {
-            Utils.debugLog(TAG, "ignoring intent with null EXTRA_APK: " + intent);
-            return;
-        }
         Installer installer = InstallerFactory.create(this, apk);
 
         if (ACTION_INSTALL.equals(intent.getAction())) {
@@ -117,7 +111,7 @@ public class InstallerService extends IntentService {
         intent.setData(localApkUri);
         intent.putExtra(Installer.EXTRA_DOWNLOAD_URI, downloadUri);
         intent.putExtra(Installer.EXTRA_APK, apk);
-        context.startService(intent);
+        enqueueWork(context, intent);
     }
 
     /**
@@ -130,7 +124,10 @@ public class InstallerService extends IntentService {
         Intent intent = new Intent(context, InstallerService.class);
         intent.setAction(ACTION_UNINSTALL);
         intent.putExtra(Installer.EXTRA_APK, apk);
-        context.startService(intent);
+        enqueueWork(context, intent);
     }
 
+    private static void enqueueWork(Context context, @NonNull Intent intent) {
+        enqueueWork(context, InstallerService.class, 0x872394, intent);
+    }
 }
diff --git a/app/src/main/java/org/fdroid/fdroid/installer/PrivilegedInstaller.java b/app/src/main/java/org/fdroid/fdroid/installer/PrivilegedInstaller.java
index 0bc880887..fee625af3 100644
--- a/app/src/main/java/org/fdroid/fdroid/installer/PrivilegedInstaller.java
+++ b/app/src/main/java/org/fdroid/fdroid/installer/PrivilegedInstaller.java
@@ -29,6 +29,7 @@ import android.content.pm.PackageManager;
 import android.net.Uri;
 import android.os.IBinder;
 import android.os.RemoteException;
+import android.support.annotation.NonNull;
 import android.util.Log;
 import org.fdroid.fdroid.Preferences;
 import org.fdroid.fdroid.R;
@@ -256,7 +257,7 @@ public class PrivilegedInstaller extends Installer {
                         "device owner has marked the package as uninstallable.");
     }
 
-    public PrivilegedInstaller(Context context, Apk apk) {
+    public PrivilegedInstaller(Context context, @NonNull Apk apk) {
         super(context, apk);
     }
 
diff --git a/app/src/main/java/org/fdroid/fdroid/localrepo/CacheSwapAppsService.java b/app/src/main/java/org/fdroid/fdroid/localrepo/CacheSwapAppsService.java
index 885c8bee2..f6452c1eb 100644
--- a/app/src/main/java/org/fdroid/fdroid/localrepo/CacheSwapAppsService.java
+++ b/app/src/main/java/org/fdroid/fdroid/localrepo/CacheSwapAppsService.java
@@ -74,8 +74,10 @@ public class CacheSwapAppsService extends IntentService {
         try {
             PackageManager pm = getPackageManager();
             String packageName = intent.getData().getSchemeSpecificPart();
-            App app = new App(this, pm, packageName);
-            SwapService.putAppInCache(packageName, app);
+            App app = App.getInstance(this, pm, packageName);
+            if (app != null) {
+                SwapService.putAppInCache(packageName, app);
+            }
         } catch (CertificateEncodingException | IOException | PackageManager.NameNotFoundException e) {
             e.printStackTrace();
         }
diff --git a/app/src/main/java/org/fdroid/fdroid/localrepo/LocalRepoManager.java b/app/src/main/java/org/fdroid/fdroid/localrepo/LocalRepoManager.java
index 6c0071054..7ea5905cc 100644
--- a/app/src/main/java/org/fdroid/fdroid/localrepo/LocalRepoManager.java
+++ b/app/src/main/java/org/fdroid/fdroid/localrepo/LocalRepoManager.java
@@ -259,9 +259,9 @@ public final class LocalRepoManager {
         try {
             app = SwapService.getAppFromCache(packageName);
             if (app == null) {
-                app = new App(context.getApplicationContext(), pm, packageName);
+                app = App.getInstance(context.getApplicationContext(), pm, packageName);
             }
-            if (!app.isValid()) {
+            if (app == null || !app.isValid()) {
                 return;
             }
         } catch (PackageManager.NameNotFoundException | CertificateEncodingException | IOException e) {
diff --git a/app/src/main/java/org/fdroid/fdroid/localrepo/SwapService.java b/app/src/main/java/org/fdroid/fdroid/localrepo/SwapService.java
index 3a16ea723..826de3736 100644
--- a/app/src/main/java/org/fdroid/fdroid/localrepo/SwapService.java
+++ b/app/src/main/java/org/fdroid/fdroid/localrepo/SwapService.java
@@ -94,7 +94,7 @@ public class SwapService extends Service {
         return INSTALLED_APPS.get(packageName);
     }
 
-    static void putAppInCache(String packageName, App app) {
+    static void putAppInCache(String packageName, @NonNull App app) {
         INSTALLED_APPS.put(packageName, app);
     }
 
diff --git a/app/src/main/java/org/fdroid/fdroid/net/ConnectivityMonitorService.java b/app/src/main/java/org/fdroid/fdroid/net/ConnectivityMonitorService.java
index 13df8ee6f..8d943a191 100644
--- a/app/src/main/java/org/fdroid/fdroid/net/ConnectivityMonitorService.java
+++ b/app/src/main/java/org/fdroid/fdroid/net/ConnectivityMonitorService.java
@@ -1,6 +1,5 @@
 package org.fdroid.fdroid.net;
 
-import android.app.IntentService;
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
@@ -8,16 +7,18 @@ import android.content.IntentFilter;
 import android.net.ConnectivityManager;
 import android.net.NetworkInfo;
 import android.os.Build;
+import android.support.annotation.NonNull;
+import android.support.v4.app.JobIntentService;
 import com.nostra13.universalimageloader.core.ImageLoader;
 import org.fdroid.fdroid.FDroidApp;
 import org.fdroid.fdroid.Preferences;
 
 /**
- * An {@link IntentService} subclass for tracking whether there is metered or
+ * An {@link JobIntentService} subclass for tracking whether there is metered or
  * unmetered internet available, based on
  * {@link android.net.ConnectivityManager#CONNECTIVITY_ACTION}
  */
-public class ConnectivityMonitorService extends IntentService {
+public class ConnectivityMonitorService extends JobIntentService {
     public static final String TAG = "ConnectivityMonitorServ";
 
     public static final int FLAG_NET_UNAVAILABLE = 0;
@@ -33,10 +34,10 @@ public class ConnectivityMonitorService extends IntentService {
         }
     };
 
-    public ConnectivityMonitorService() {
-        super("ConnectivityMonitorService");
-    }
-
+    /**
+     * Register the {@link BroadcastReceiver} which also starts this
+     * {@code Service} since it is a sticky broadcast.
+     */
     public static void registerAndStart(Context context) {
         context.registerReceiver(CONNECTIVITY_RECEIVER, new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION));
     }
@@ -44,7 +45,7 @@ public class ConnectivityMonitorService extends IntentService {
     public static void start(Context context) {
         Intent intent = new Intent(context, ConnectivityMonitorService.class);
         intent.setAction(ACTION_START);
-        context.startService(intent);
+        enqueueWork(context, ConnectivityMonitorService.class, 0x982ae7b, intent);
     }
 
     /**
@@ -77,8 +78,8 @@ public class ConnectivityMonitorService extends IntentService {
     }
 
     @Override
-    protected void onHandleIntent(Intent intent) {
-        if (intent != null && ACTION_START.equals(intent.getAction())) {
+    protected void onHandleWork(@NonNull Intent intent) {
+        if (ACTION_START.equals(intent.getAction())) {
             FDroidApp.networkState = getNetworkState(this);
             ImageLoader.getInstance().denyNetworkDownloads(!Preferences.get().isBackgroundDownloadAllowed());
         }
diff --git a/app/src/main/java/org/fdroid/fdroid/net/WifiStateChangeService.java b/app/src/main/java/org/fdroid/fdroid/net/WifiStateChangeService.java
index cdc99524f..023524a9a 100644
--- a/app/src/main/java/org/fdroid/fdroid/net/WifiStateChangeService.java
+++ b/app/src/main/java/org/fdroid/fdroid/net/WifiStateChangeService.java
@@ -47,7 +47,7 @@ import java.util.Locale;
  * This also schedules an update to encourage updates happening on
  * unmetered networks like typical WiFi rather than networks that can
  * cost money or have caps.  The logic for checking the state of the
- * internet connection is in {@link org.fdroid.fdroid.UpdateService#onHandleIntent(Intent)}
+ * internet connection is in {@link org.fdroid.fdroid.UpdateService#onHandleWork(Intent)}
  * <p>
  * Some devices send multiple copies of given events, like a Moto G often
  * sends three {@code CONNECTED} events.  So they have to be debounced to
diff --git a/app/src/main/java/org/fdroid/fdroid/views/AppDetailsRecyclerViewAdapter.java b/app/src/main/java/org/fdroid/fdroid/views/AppDetailsRecyclerViewAdapter.java
index 12ffd19bc..9a82a6947 100644
--- a/app/src/main/java/org/fdroid/fdroid/views/AppDetailsRecyclerViewAdapter.java
+++ b/app/src/main/java/org/fdroid/fdroid/views/AppDetailsRecyclerViewAdapter.java
@@ -450,19 +450,24 @@ public class AppDetailsRecyclerViewAdapter
                     }
                 }
             });
-            if (app.antiFeatures != null) {
+            if (app.antiFeatures != null && app.antiFeatures.length > 0) {
                 StringBuilder sb = new StringBuilder();
+                sb.append("<ul>");
                 for (String af : app.antiFeatures) {
                     String afdesc = descAntiFeature(af);
-                    sb.append("\t• ").append(afdesc).append('\n');
-                }
-                if (sb.length() > 0) {
-                    sb.setLength(sb.length() - 1);
-                    antiFeaturesView.setText(sb.toString());
-                } else {
-                    antiFeaturesView.setVisibility(View.GONE);
+                    sb.append("<li><a href=\"https://f-droid.org/wiki/page/Antifeature:")
+                            .append(af)
+                            .append("\">")
+                            .append(afdesc)
+                            .append("</a></li>");
                 }
+                sb.append("</ul>");
+                antiFeaturesView.setText(Html.fromHtml(sb.toString()));
+                antiFeaturesView.setMovementMethod(LinkMovementMethod.getInstance());
+            } else {
+                antiFeaturesView.setVisibility(View.GONE);
             }
+
             updateAntiFeaturesWarning();
             buttonSecondaryView.setText(R.string.menu_uninstall);
             buttonSecondaryView.setVisibility(app.isUninstallable(context) ? View.VISIBLE : View.INVISIBLE);
@@ -538,6 +543,10 @@ public class AppDetailsRecyclerViewAdapter
                     return itemView.getContext().getString(R.string.antiupstreamnonfreelist);
                 case "NonFreeAssets":
                     return itemView.getContext().getString(R.string.antinonfreeassetslist);
+                case "DisabledAlgorithm":
+                    return itemView.getContext().getString(R.string.antidisabledalgorithmlist);
+                case "KnownVuln":
+                    return itemView.getContext().getString(R.string.antiknownvulnlist);
                 default:
                     return af;
             }
@@ -664,7 +673,8 @@ public class AppDetailsRecyclerViewAdapter
             contentView = (LinearLayout) view.findViewById(R.id.ll_content);
         }
 
-        protected abstract @DrawableRes int getIcon();
+        @DrawableRes
+        protected abstract int getIcon();
 
         /**
          * Depending on whether we are expanded or not, update the icon which indicates whether the
@@ -694,7 +704,8 @@ public class AppDetailsRecyclerViewAdapter
             updateExpandableItem(showVersions);
         }
 
-        protected @DrawableRes int getIcon() {
+        @DrawableRes
+        protected int getIcon() {
             return R.drawable.ic_access_time_24dp_grey600;
         }
     }
@@ -794,7 +805,8 @@ public class AppDetailsRecyclerViewAdapter
             contentView.addView(perms.getPermissionsView(AppSecurityPermissions.WHICH_ALL));
         }
 
-        protected @DrawableRes int getIcon() {
+        @DrawableRes
+        protected int getIcon() {
             return R.drawable.ic_lock_24dp_grey600;
         }
     }
@@ -867,7 +879,8 @@ public class AppDetailsRecyclerViewAdapter
             }
         }
 
-        protected @DrawableRes int getIcon() {
+        @DrawableRes
+        protected int getIcon() {
             return R.drawable.ic_website;
         }
     }
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index f8181bc7f..a27bfa507 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -203,6 +203,8 @@ This often occurs with apps installed via Google Play or other sources, if they
     <string name="antinonfreedeplist">This app depends on other non-free apps</string>
     <string name="antiupstreamnonfreelist">The upstream source code is not entirely Free</string>
     <string name="antinonfreeassetslist">This app contains non-free assets</string>
+    <string name="antidisabledalgorithmlist">This app has a weak security signature</string>
+    <string name="antiknownvulnlist">This app contains a known security vulnerability</string>
 
     <string name="display">Display</string>