Real Speed Gun is described as 'This app is used to calculate the speed of moving objects. You can measure the speed of pedestrians, cars, bicycles and anything moving of Earth's surface'. There are five alternatives to Real Speed Gun for iPhone, Blackberry, Windows Phone and Android. The best alternative is Traffic Speed Gun. It's not free, so if you're looking for a free alternative, you could try IOYY Speed Gun or Speed Gun. Other great apps like Real Speed Gun are SoundSpeedGun (Paid) and iSpeed Gun (Paid).
For those who were always interested in how fast is an airplane flying around them, a car driving or RC model driving. Speed gun uses sound, emitted by moving object to determine its speed. It uses Doppler effect.
Speed Gun (Smart Speed) can measure the speed of a moving object by touch. Thera are several apps in the market. All of them are for the baseball. just ball speed. This speedometer can measure the speed of a moving object by touch.