I suppose the proper way would be to change the activity into a Service then use the startService() method, but this came up in when I Googled. Oh’so much less coding and I was back to work in seconds.

Change this:

<activity  android:name=".RingBellActivity"></activity>

To

<activity  android:name=".RingBellActivity"  android:theme="@android:style/Theme.NoDisplay"></activity>