Interesting application for geeks, for measuring speed of cars or RC airplanes. Seems like it uses sound generated by object flying or driving around and doppler effect.
If you know how to use it its kind of precise.
Sound Speed Gun
SoundSpeedGun | Windows Phone Apps+Games Store (United States)
If you know how to use it its kind of precise.
Sound Speed Gun
SoundSpeedGun | Windows Phone Apps+Games Store (United States)