Speed Gun

Speed Gun will let you measure the speed of objects like a real laser gun. You only need to input relative camera height and then aim at the target for a couple of seconds. Speed and distance are calculated with smart mathematical algorithms.

This is probably the best speed gun app out there, because you only need to know relative camera height and there is no limitations about moving direction of the target. Measuring with that speed gun is as close as possible to measuring with a laser speed gun.