When it's dark people need a simple source of light.
Flashlight changes the dual screens of your Nintendo DSi into a flashlight with added features. Change the colour and the intensity of the light and use your Nintendo DSi to read under the blanket or as a source of light while taking a night stroll.
The other modes of Flashlight could even be helpful in stranded situations - use the warning light if your car breaks down - or how about turning on the S.O.S. mode to send out a signal the next time your plane has to land on a deserted island!