Default [APP][2.1+] SpeedProof - Speedometer

Some people have beat speeding tickets in the past with GPS loggers, this app logs your current speed, location and so on to a GPX file as fast as the GPS chip updates the system, but unlike other GPS loggers uses cryptography to make a tamper proof log which you can use to prove your speed.

This is the official help thread for the app.

You can download from the play store