Flsh is one of the most (if not the most) lightweight App for controlling your LED light on your Android mobile phone.
The app has four modes:
1. Turn the LED on/off and using it as a light
2. Let the LED blink where you can adjust the speed
3. Blink as pre recorded effects or to write in Morse Code
4. Turning your Screen to what ever color you want. Useful in video recordings with special effects (green room/screen)
I designed it and got help from my friend Damjan with Android development.