This application is demonstrate the use of flashlight of the camera.

You can find complete tutorial of it here: http://acomputerengineer.wordpress.com/2013/09/12/turn-on-and-turn-off-flash-light-programmatically-in-android/

You can download this app from Google Play: https://play.google.com/store/apps/details?id=com.dakshbhatt21.flashlightdemo

If you have any question, ask them on the above article on this blog http://acomputerengineer.wordpress.com