diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 7f788ff..39c7de0 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -3,6 +3,8 @@
     package="org.secuso.privacyfriendlybreakreminder">
 
     <uses-permission android:name="android.permission.VIBRATE" />
+    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
+    <uses-permission android:name="android.permission.WAKE_LOCK" />
 
     <application
         android:allowBackup="true"
@@ -111,6 +113,14 @@
             android:enabled="true"
             android:exported="false" />
 
+        <receiver android:name=".receivers.OnBootCompletedReceiver">
+            <intent-filter>
+                <action android:name="android.intent.action.BOOT_COMPLETED" />
+            </intent-filter>
+        </receiver>
+
+        <receiver android:name=".receivers.TimerSchedulerReceiver"/>
+
     </application>
 
 </manifest>
\ No newline at end of file
diff --git a/app/src/main/java/org/secuso/privacyfriendlybreakreminder/activities/ExerciseActivity.java b/app/src/main/java/org/secuso/privacyfriendlybreakreminder/activities/ExerciseActivity.java
index b5696b6..9245622 100644
--- a/app/src/main/java/org/secuso/privacyfriendlybreakreminder/activities/ExerciseActivity.java
+++ b/app/src/main/java/org/secuso/privacyfriendlybreakreminder/activities/ExerciseActivity.java
@@ -139,23 +139,23 @@ public class ExerciseActivity extends AppCompatActivity implements android.suppo
 
     private void initResources() {
         dbHelper = new SQLiteHelper(this);
-        playButton = findViewById(R.id.button_playPause);
-        progressBar = findViewById(R.id.progressBar);
-        timerText = findViewById(R.id.timerText);
-        executionText = findViewById(R.id.execution);
-        descriptionText = findViewById(R.id.description);
-        exerciseImage = findViewById(R.id.exercise_image);
-        sectionText = findViewById(R.id.section);
-        repeatButton = findViewById(R.id.button_repeat);
-        exerciseContent = findViewById(R.id.exercise_layout);
-        continuousButton = findViewById(R.id.button_continuous);
-        prevButton = findViewById(R.id.button_prev);
-        nextButton = findViewById(R.id.button_next);
-        exerciseInfoButton = findViewById(R.id.exercise_info_button);
+        playButton = (ImageButton) findViewById(R.id.button_playPause);
+        progressBar = (ProgressBar) findViewById(R.id.progressBar);
+        timerText = (TextView) findViewById(R.id.timerText);
+        executionText = (TextView) findViewById(R.id.execution);
+        descriptionText = (TextView) findViewById(R.id.description);
+        exerciseImage = (ImageView) findViewById(R.id.exercise_image);
+        sectionText = (TextView) findViewById(R.id.section);
+        repeatButton = (ImageButton) findViewById(R.id.button_repeat);
+        exerciseContent = (ConstraintLayout) findViewById(R.id.exercise_layout);
+        continuousButton = (ImageButton) findViewById(R.id.button_continuous);
+        prevButton = (ImageButton) findViewById(R.id.button_prev);
+        nextButton = (ImageButton) findViewById(R.id.button_next);
+        exerciseInfoButton = (ImageButton) findViewById(R.id.exercise_info_button);
 
-        progressBarBig = findViewById(R.id.progressBarBig);
-        breakTimerTextBig = findViewById(R.id.breakTimerTextBig);
-        bigProgressBarLayout = findViewById(R.id.bigProgressBarLayout);
+        progressBarBig = (ProgressBar) findViewById(R.id.progressBarBig);
+        breakTimerTextBig = (TextView) findViewById(R.id.breakTimerTextBig);
+        bigProgressBarLayout = (ConstraintLayout) findViewById(R.id.bigProgressBarLayout);
 
         setRepeatButtonStatus(repeatStatus);
         setContinuousButtonStatus(continuousStatus);
diff --git a/app/src/main/java/org/secuso/privacyfriendlybreakreminder/service/TimerService.java b/app/src/main/java/org/secuso/privacyfriendlybreakreminder/service/TimerService.java
index 7db5ecd..67aa302 100644
--- a/app/src/main/java/org/secuso/privacyfriendlybreakreminder/service/TimerService.java
+++ b/app/src/main/java/org/secuso/privacyfriendlybreakreminder/service/TimerService.java
@@ -12,7 +12,10 @@ import android.content.SharedPreferences;
 import android.os.Binder;
 import android.os.Bundle;
 import android.os.CountDownTimer;
+import android.os.Handler;
+import android.os.HandlerThread;
 import android.os.IBinder;
+import android.os.Looper;
 import android.preference.PreferenceManager;
 import android.provider.Settings;
 import android.support.v4.app.NotificationCompat;
@@ -115,7 +118,7 @@ public class TimerService extends Service {
                 .setWhen(0)
                 .setOngoing(false)
                 .setAutoCancel(true)
-                .setSmallIcon(R.mipmap.ic_launcher)
+                .setSmallIcon(R.mipmap.ic_notification)
                 .setDefaults(Notification.DEFAULT_LIGHTS)
                 .setVibrate(new long[] { 0, 1000, 1000, 1000, 1000, 1000, 1000 })
                 .setSound(Settings.System.DEFAULT_NOTIFICATION_URI)
@@ -153,7 +156,7 @@ public class TimerService extends Service {
         unregisterReceiver(notificationPreferenceChangedReceiver);
     }
 
-    public synchronized void startTimer(long duration) {
+    public synchronized void startTimer(final long duration) {
         if(!isRunning) {
             initialDuration = duration;
 
@@ -170,10 +173,11 @@ public class TimerService extends Service {
                 sendBroadcast(broadcast);
             }
         }
+
     }
 
     public synchronized void pauseTimer() {
-        if(isRunning) {
+        if (isRunning) {
             mTimer.cancel();
             isRunning = false;
 
@@ -192,7 +196,7 @@ public class TimerService extends Service {
     }
 
     public synchronized void resetTimer() {
-        if(isRunning) {
+        if (isRunning) {
             mTimer.cancel();
             mTimer = createTimer(initialDuration);
             mTimer.start();
@@ -203,7 +207,7 @@ public class TimerService extends Service {
     }
 
     public synchronized void stopAndResetTimer() {
-        if(isRunning) mTimer.cancel();
+        if (isRunning) mTimer.cancel();
         isRunning = false;
         remainingDuration = initialDuration;
 
@@ -263,7 +267,7 @@ public class TimerService extends Service {
 
         if (intent != null) {
 
-            String action = intent.getAction();
+            final String action = intent.getAction();
 
             if      (ACTION_START_TIMER.equals(action))     handleRestartTimer();
             else if (ACTION_PAUSE_TIMER.equals(action))     pauseTimer();
@@ -314,7 +318,7 @@ public class TimerService extends Service {
         builder.setPriority(NotificationCompat.PRIORITY_DEFAULT);
         builder.setWhen(0);
         builder.setProgress((int) initialDuration, (int) (initialDuration - remainingDuration), false);
-        builder.setSmallIcon(R.mipmap.ic_launcher);
+        builder.setSmallIcon(R.mipmap.ic_notification);
         builder.setOngoing(isRunning() || isPaused());
 
         Intent intent = new Intent(this, TimerActivity.class);