TempoMaster is a GPS speedometer that allows you to overlay the speed information in realtime on top of other navigational map apps. It will display your current speed versus the allowed one. It uses data from OpenStreetMap to display realtime information. Features:

• Display the current car speed and the maximum permissible speed
• Customizable speed indicator and display
• The app works offline while driving
• Can run concurrently with another app (i.e. Google Maps)
• Overlay the app on top of other apps or show in full screen
• Automatic start/stop with Bluetooth
• Worldwide support