This app might not work indoors and places where the GPS signals are obstructed. The time to load the app depends on your device and the GPS signal strength.
During quick acceleration and deceleration the speed measurement might be little off, but at reasonably steady speed, the measurement should be as accurate as any other GPS based device.
This app is for information purpose only. Do not completely rely on the information it provides. Please obey traffic rules and keep your eyes on the road while driving.
Keywords: speedometer, digital, digital speedometer, simple speedometer, speed.