If you are looking for a simple, bare bones Windows Phone 8 app to turn your camera LED light into a strobe light, take a look at FlashStrobe. Not sure it could get any more simpler.
The one screen app has a settings bar to regulate the strobe speed. You can set your Windows Phone light to flash any where from 0 to 20 flashes per second. Once you've set the pace, just tap the screen to turn on the strobe.
The strobe rate can be adjusted while the light is flashing and to turn off the light, just tap the screen a second time. Uses for FlashStrobe? Dim the lights at the party and have a '70's disco moment or use FlashStrobe as an emergency beacon if stranded on the side of the road.
FlashStrobe is a free Windows Phone 8 app and you can find it here at the Windows Phone Store.