oh i got mine to spent 30 bucks and 5for the app and loving it. Use it with my htc evo design 4g and make sure you download this pluggin. this lets you record video while you driving and the speed and any other sensor you put on the screen. Here is a youtube video of some one using it.
http://www.youtube.com/watch?v=RWIP9...eature=related https://play.google.com/store/apps/d...5yZWNvcmRlciJd