This app monitors your movement speed by using the GPS, continues to display.And when you exceed the set speed, or when you fall below the set speed,app warn with vibration and sound.It is useful to prevent a speeding while driving a car.Or, it can be used to maintain a certain level of speed when you are walking or jogging or cycling.You can chose speed units , MPH(miles per hour), km/h(kilometers per hour), m/min(meters per minutes).Timing of the warning, "exceeds the set speed" and "falls below the set speed" can choose from two.Start measurement by pressing "Velocimetry" button in the middle of the screen.During measurement can be run in the background when you close the window.