Aflashlight app is one of the canonical simple apps that anybody can create. The idea is that the app makes the screen completely white, so the screen itself becomes a decent flashlight when it’s dark. (Another variation would be a “mirror” app that makes the screen completely black!) Certainly a “blank white screen” app is even simpler to implement than the Tally app. But this chapter’s Flashlight app is no ordinary flashlight! It supports custom colors, flashing SOS in Morse code, and even a strobe light mode!

Can my app turn on the phone camera’s flash and use that as a real flashlight?

No, this is not currently supported. Leveraging the light from the screen is the best you can do.

Creating this multi-mode application gives a good opportunity to understand and use the application bar, a central part of the Windows Phone experience.