diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 8e3761b..addf8dd 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -11,22 +11,22 @@
     
     <application android:label="@string/app_name" android:icon="@drawable/ic_launcher" android:allowBackup="true" android:theme="@style/TraccarTheme">
         
-        <activity android:name="TraccarActivity">
+        <activity android:name=".MainActivity">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
 
-        <activity android:name="StatusActivity">
+        <activity android:name=".StatusActivity">
         </activity>
 
-        <activity android:name="AboutActivity">
+        <activity android:name=".AboutActivity">
         </activity>
         
-        <service android:name="TraccarService" />
+        <service android:name=".TraccarService" />
         
-        <receiver android:name="AutostartReceiver">
+        <receiver android:name=".AutostartReceiver">
             <intent-filter>
                 <action android:name="android.intent.action.BOOT_COMPLETED" />
             </intent-filter>
diff --git a/app/src/main/java/org/traccar/client/AutostartReceiver.java b/app/src/main/java/org/traccar/client/AutostartReceiver.java
index e9c0011..f87d2ac 100644
--- a/app/src/main/java/org/traccar/client/AutostartReceiver.java
+++ b/app/src/main/java/org/traccar/client/AutostartReceiver.java
@@ -28,7 +28,7 @@ public class AutostartReceiver extends BroadcastReceiver {
     @Override
     public void onReceive(Context context, Intent intent) {
     	SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(context);
-    	if (sharedPreferences.getBoolean(TraccarActivity.KEY_STATUS, false)) {
+    	if (sharedPreferences.getBoolean(MainActivity.KEY_STATUS, false)) {
     		context.startService(new Intent(context, TraccarService.class));
     	}
     }
diff --git a/app/src/main/java/org/traccar/client/TraccarActivity.java b/app/src/main/java/org/traccar/client/MainActivity.java
similarity index 77%
rename from app/src/main/java/org/traccar/client/TraccarActivity.java
rename to app/src/main/java/org/traccar/client/MainActivity.java
index 2d2b9ac..652d877 100644
--- a/app/src/main/java/org/traccar/client/TraccarActivity.java
+++ b/app/src/main/java/org/traccar/client/MainActivity.java
@@ -28,7 +28,7 @@ import android.view.Menu;
 import android.view.MenuItem;
 
 @SuppressWarnings("deprecation")
-public class TraccarActivity extends PreferenceActivity {
+public class MainActivity extends PreferenceActivity implements OnSharedPreferenceChangeListener {
 
     public static final String LOG_TAG = "traccar";
 
@@ -45,23 +45,21 @@ public class TraccarActivity extends PreferenceActivity {
         super.onCreate(savedInstanceState);
         addPreferencesFromResource(R.xml.preferences);
         initPreferences();
-        SharedPreferences sharedPreferences = getPreferenceScreen().getSharedPreferences();
-        if (sharedPreferences.getBoolean(KEY_STATUS, false))
+        if (getPreferenceScreen().getSharedPreferences().getBoolean(KEY_STATUS, false)) {
             startService(new Intent(this, TraccarService.class));
+        }
     }
 
     @Override
     protected void onResume() {
         super.onResume();
-        getPreferenceScreen().getSharedPreferences().registerOnSharedPreferenceChangeListener(
-                preferenceChangeListener);
+        getPreferenceScreen().getSharedPreferences().registerOnSharedPreferenceChangeListener(this);
     }
 
     @Override
     protected void onPause() {
-        getPreferenceScreen().getSharedPreferences().unregisterOnSharedPreferenceChangeListener(
-                preferenceChangeListener);
         super.onPause();
+        getPreferenceScreen().getSharedPreferences().unregisterOnSharedPreferenceChangeListener(this);
     }
 
     private void setPreferencesEnabled(boolean enabled) {
@@ -74,22 +72,20 @@ public class TraccarActivity extends PreferenceActivity {
         preferenceScreen.findPreference(KEY_EXTENDED).setEnabled(enabled);
     }
 
-    OnSharedPreferenceChangeListener preferenceChangeListener = new OnSharedPreferenceChangeListener() {
-        @Override
-        public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
-            if (key.equals(KEY_STATUS)) {
-                if (sharedPreferences.getBoolean(KEY_STATUS, false)) {
-                    setPreferencesEnabled(false);
-                    startService(new Intent(TraccarActivity.this, TraccarService.class));
-                } else {
-                    stopService(new Intent(TraccarActivity.this, TraccarService.class));
-                    setPreferencesEnabled(true);
-                }
-            } else if (key.equals(KEY_ID)) {
-                findPreference(KEY_ID).setSummary(sharedPreferences.getString(KEY_ID, null));
+    @Override
+    public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
+        if (key.equals(KEY_STATUS)) {
+            if (sharedPreferences.getBoolean(KEY_STATUS, false)) {
+                setPreferencesEnabled(false);
+                startService(new Intent(this, TraccarService.class));
+            } else {
+                stopService(new Intent(this, TraccarService.class));
+                setPreferencesEnabled(true);
             }
+        } else if (key.equals(KEY_ID)) {
+            findPreference(KEY_ID).setSummary(sharedPreferences.getString(KEY_ID, null));
         }
-    };
+    }
 
     @Override
     public boolean onCreateOptionsMenu(Menu menu) {
diff --git a/app/src/main/java/org/traccar/client/StatusActivity.java b/app/src/main/java/org/traccar/client/StatusActivity.java
index 3ca2d42..772e71a 100644
--- a/app/src/main/java/org/traccar/client/StatusActivity.java
+++ b/app/src/main/java/org/traccar/client/StatusActivity.java
@@ -43,7 +43,7 @@ public class StatusActivity extends ListActivity {
     }
 
     public static void addMessage(String message) {
-        Log.i(TraccarActivity.LOG_TAG, message);
+        Log.i(MainActivity.LOG_TAG, message);
         DateFormat format = DateFormat.getTimeInstance(DateFormat.SHORT);
         message = format.format(new Date()) + " - " + message;
         messages.add(message);
diff --git a/app/src/main/java/org/traccar/client/TraccarService.java b/app/src/main/java/org/traccar/client/TraccarService.java
index 55a5656..6d8473d 100644
--- a/app/src/main/java/org/traccar/client/TraccarService.java
+++ b/app/src/main/java/org/traccar/client/TraccarService.java
@@ -62,12 +62,12 @@ public class TraccarService extends Service {
         sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
 
         try {
-            id = sharedPreferences.getString(TraccarActivity.KEY_ID, null);
-            address = sharedPreferences.getString(TraccarActivity.KEY_ADDRESS, null);
-            provider = sharedPreferences.getString(TraccarActivity.KEY_PROVIDER, null);
-            port = Integer.valueOf(sharedPreferences.getString(TraccarActivity.KEY_PORT, null));
-            interval = Integer.valueOf(sharedPreferences.getString(TraccarActivity.KEY_INTERVAL, null));
-            extended = sharedPreferences.getBoolean(TraccarActivity.KEY_EXTENDED, false);
+            id = sharedPreferences.getString(MainActivity.KEY_ID, null);
+            address = sharedPreferences.getString(MainActivity.KEY_ADDRESS, null);
+            provider = sharedPreferences.getString(MainActivity.KEY_PROVIDER, null);
+            port = Integer.valueOf(sharedPreferences.getString(MainActivity.KEY_PORT, null));
+            interval = Integer.valueOf(sharedPreferences.getString(MainActivity.KEY_INTERVAL, null));
+            extended = sharedPreferences.getBoolean(MainActivity.KEY_EXTENDED, false);
         } catch (Exception error) {
             Log.w(LOG_TAG, error);
         }
@@ -135,38 +135,38 @@ public class TraccarService extends Service {
         public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
             StatusActivity.addMessage(getString(R.string.status_preference_update));
             try {
-                if (key.equals(TraccarActivity.KEY_ADDRESS)) {
+                if (key.equals(MainActivity.KEY_ADDRESS)) {
 
-                    address = sharedPreferences.getString(TraccarActivity.KEY_ADDRESS, null);
+                    address = sharedPreferences.getString(MainActivity.KEY_ADDRESS, null);
                     clientController.setNewServer(address, port);
 
-                } else if (key.equals(TraccarActivity.KEY_PORT)) {
+                } else if (key.equals(MainActivity.KEY_PORT)) {
 
-                    port = Integer.valueOf(sharedPreferences.getString(TraccarActivity.KEY_PORT, null));
+                    port = Integer.valueOf(sharedPreferences.getString(MainActivity.KEY_PORT, null));
                     clientController.setNewServer(address, port);
 
-                } else if (key.equals(TraccarActivity.KEY_INTERVAL)) {
+                } else if (key.equals(MainActivity.KEY_INTERVAL)) {
 
-                    interval = Integer.valueOf(sharedPreferences.getString(TraccarActivity.KEY_INTERVAL, null));
+                    interval = Integer.valueOf(sharedPreferences.getString(MainActivity.KEY_INTERVAL, null));
                     positionProvider.stopUpdates();
                     positionProvider = new PositionProvider(TraccarService.this, provider, interval * 1000, positionListener);
                     positionProvider.startUpdates();
 
-                } else if (key.equals(TraccarActivity.KEY_ID)) {
+                } else if (key.equals(MainActivity.KEY_ID)) {
 
-                    id = sharedPreferences.getString(TraccarActivity.KEY_ID, null);
+                    id = sharedPreferences.getString(MainActivity.KEY_ID, null);
                     clientController.setNewLogin(ProtocolFormatter.createLoginMessage(id));
 
-                } else if (key.equals(TraccarActivity.KEY_PROVIDER)) {
+                } else if (key.equals(MainActivity.KEY_PROVIDER)) {
 
-                    provider = sharedPreferences.getString(TraccarActivity.KEY_PROVIDER, null);
+                    provider = sharedPreferences.getString(MainActivity.KEY_PROVIDER, null);
                     positionProvider.stopUpdates();
                     positionProvider = new PositionProvider(TraccarService.this, provider, interval * 1000, positionListener);
                     positionProvider.startUpdates();
 
-                } else if (key.equals(TraccarActivity.KEY_EXTENDED)) {
+                } else if (key.equals(MainActivity.KEY_EXTENDED)) {
 
-                    extended = sharedPreferences.getBoolean(TraccarActivity.KEY_EXTENDED, false);
+                    extended = sharedPreferences.getBoolean(MainActivity.KEY_EXTENDED, false);
 
                 }
             } catch (Exception error) {