Automatically toggles to Gurmukhi mode with my application called "Gurbani Searcher".
Please follow following steps to enable the keyboard:-
Android version < 4.0
1. Settings-->click Language & Keyboard on phone
2. Select Gurbani keyboard from the list.
3. Go to Gurbani Searcher application(or any text field)
4. Long click on the text field.
5. Select Inputmethod
6. Select Gurmukhi keyboard.
7. System will display warning, ...