diff --git a/MessengerProj/src/main/AndroidManifest.xml b/MessengerProj/src/main/AndroidManifest.xml
index bba8ecb3d..6d9006c27 100644
--- a/MessengerProj/src/main/AndroidManifest.xml
+++ b/MessengerProj/src/main/AndroidManifest.xml
@@ -157,15 +157,18 @@
         </receiver>
         -->
 
-        <!-- <service android:name=".AuthenticatorService" android:exported="true">
+        <!-- currently, we do not use the android account system
+        <service android:name=".AuthenticatorService" android:exported="true">
             <intent-filter>
                 <action android:name="android.accounts.AccountAuthenticator"/>
             </intent-filter>
             <meta-data android:name="android.accounts.AccountAuthenticator"
                 android:resource="@xml/auth"/>
-        </service> - currently, we do not use the android account system -->
+        </service>
+        -->
 
-        <service android:name=".ContactsSyncAdapterService" android:exported="true"> <!-- what is this for? (bp) -->
+        <!-- seems to be not needed (bp)
+        <service android:name=".ContactsSyncAdapterService" android:exported="true">
             <intent-filter>
                 <action android:name="android.content.SyncAdapter" />
             </intent-filter>
@@ -174,6 +177,7 @@
             <meta-data android:name="android.provider.CONTACTS_STRUCTURE"
                 android:resource="@xml/contacts" />
         </service>
+        -->
 
         <!-- this would implement the "direct share" functionality (the system shows some direct links eg.
         to the most recent chats when calling "share" from another app, see https://developer.android.com/reference/android/service/chooser/ChooserTargetService.html )
@@ -192,11 +196,13 @@
         <service android:name=".ClearCacheService" android:exported="false"/>
         <service android:name=".VideoEncodingService" android:enabled="true"/>
         <service android:name=".MusicPlayerService" android:exported="true" android:enabled="true"/>
-        <!-- <service android:name=".MusicBrowserService" android:exported="true">
+        <!-- Do not expose data through MediaBrowserService, this seems unexpected for an messenger.
+        Instead, the user can use 'save to music' or 'share' explicitly for items not privacy related.
+        <service android:name=".MusicBrowserService" android:exported="true">
             <intent-filter>
                 <action android:name="android.media.browse.MediaBrowserService"/>
             </intent-filter>
-        </service> - Do not expose data through MediaBrowserService, this seems unexpected for an messenger. Instead, the user can use 'save to music' or 'share' explicitly for items not privacy related. -->
+        </service> -->
 
         <receiver android:name=".MusicPlayerReceiver" >
             <intent-filter>
@@ -220,7 +226,9 @@
         <receiver android:name=".WearReplyReceiver" android:enabled="true"/>
         <!-- <receiver android:name=".NetworkAlarm" android:enabled="true"/> -->
 
-        <!-- <receiver android:name=".ShareBroadcastReceiver" android:enabled="true"/> - seems to be unneeded (bp) -->
+        <!-- seems to be unneeded (bp)
+        <receiver android:name=".ShareBroadcastReceiver" android:enabled="true"/>
+        -->
 
         <receiver android:name=".NotificationDismissReceiver" android:exported="false"/>
 
diff --git a/MessengerProj/src/main/java/com/b44t/messenger/ContactsSyncAdapterService.java b/MessengerProj/src/main/java/com/b44t/messenger/ContactsSyncAdapterService.java
deleted file mode 100644
index ef3c289ae..000000000
--- a/MessengerProj/src/main/java/com/b44t/messenger/ContactsSyncAdapterService.java
+++ /dev/null
@@ -1,78 +0,0 @@
-/*******************************************************************************
- *
- *                          Messenger Android Frontend
- *                        (C) 2013-2016 Nikolai Kudashov
- *                           (C) 2017 Björn Petersen
- *                    Contact: r10s@b44t.com, http://b44t.com
- *
- * This program is free software: you can redistribute it and/or modify it under
- * the terms of the GNU General Public License as published by the Free Software
- * Foundation, either version 3 of the License, or (at your option) any later
- * version.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
- * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
- * details.
- *
- * You should have received a copy of the GNU General Public License along with
- * this program.  If not, see http://www.gnu.org/licenses/ .
- *
- ******************************************************************************/
-
-
-package com.b44t.messenger;
-
-import android.accounts.Account;
-import android.accounts.OperationCanceledException;
-import android.app.Service;
-import android.content.AbstractThreadedSyncAdapter;
-import android.content.ContentProviderClient;
-import android.content.Context;
-import android.content.Intent;
-import android.content.SyncResult;
-import android.os.Bundle;
-import android.os.IBinder;
-
-public class ContactsSyncAdapterService extends Service {
-    private static SyncAdapterImpl sSyncAdapter = null;
-
-    public ContactsSyncAdapterService() {
-        super();
-    }
-
-    private static class SyncAdapterImpl extends AbstractThreadedSyncAdapter {
-        private Context mContext;
-
-        public SyncAdapterImpl(Context context) {
-            super(context, true);
-            mContext = context;
-        }
-
-        @Override
-        public void onPerformSync(Account account, Bundle extras, String authority, ContentProviderClient provider, SyncResult syncResult) {
-            try {
-                ContactsSyncAdapterService.performSync(mContext, account, extras, authority, provider, syncResult);
-            } catch (OperationCanceledException e) {
-                FileLog.e("messenger", e);
-            }
-        }
-    }
-
-    @Override
-    public IBinder onBind(Intent intent) {
-        return getSyncAdapter().getSyncAdapterBinder();
-    }
-
-    private SyncAdapterImpl getSyncAdapter() {
-        if (sSyncAdapter == null) {
-            sSyncAdapter = new SyncAdapterImpl(this);
-        }
-        return sSyncAdapter;
-    }
-
-    private static void performSync(Context context, Account account, Bundle extras, String authority, ContentProviderClient provider, SyncResult syncResult)
-            throws OperationCanceledException {
-        FileLog.d("messenger", "performSync: " + account.toString());
-    }
-}
diff --git a/MessengerProj/src/main/res/xml/contacts.xml b/MessengerProj/src/main/res/xml/contacts.xml
deleted file mode 100644
index 067b97e92..000000000
--- a/MessengerProj/src/main/res/xml/contacts.xml
+++ /dev/null
@@ -1,9 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-
-<ContactsSource xmlns:android="http://schemas.android.com/apk/res/android">
-    <ContactsDataKind android:icon="@drawable/ic_launcher"
-        android:mimeType="vnd.android.cursor.item/vnd.com.b44t.messenger.android.profile"
-        android:summaryColumn="data2"
-        android:detailColumn="data3"
-        android:detailSocialSummary="true"/>
-</ContactsSource>
diff --git a/MessengerProj/src/main/res/xml/sync_contacts.xml b/MessengerProj/src/main/res/xml/sync_contacts.xml
deleted file mode 100644
index f7cff0cbe..000000000
--- a/MessengerProj/src/main/res/xml/sync_contacts.xml
+++ /dev/null
@@ -1,3 +0,0 @@
-<sync-adapter xmlns:android="http://schemas.android.com/apk/res/android"
-    android:contentAuthority="com.android.contacts"
-    android:accountType="com.b44t.messenger"/>
\ No newline at end of file