This app turns on your phone's LED flash. Exiting the app turns it off.
Due to the extreme simplicity of the app, it's less than 100kB - a near-instant download!
Send me an email if you're seeing this app even though your phone doesn't have a flash, or if it just doesn't work on your phone. No guarantees that I can make it work on every phone, but I'll give it a shot.
It's open-source: https://bitbucket.org/nkorth/android-flashlight