<service
            android:name=".GPSTracker"
            android:enabled="true">
</service>

public class GPSTracker extends Service implements LocationListener {

    @TargetApi(Build.VERSION_CODES.M)
    public int onStartCommand(Intent intent, int flags, int startId) {

   return super.onStartCommand(intent, flags, startId);
   }

    @Override
    public void onDestroy() {
    }

    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }
}