Hold your device securely, motion your arm as if you were throwing a baseball pitch and Baseball Speed will display the actual speed of your movement in mph or kmh. Baseball Speed uses the accurate multi-axis accelerometer of your Android phone to measure, calculate, and display the speed. Nolan Ryan holds the world record at 100.9 mph, can you beat that?PLEASE READThis application is largely dependent on the accuracy and range of the accelerometer sensor. The performance characteristics of the accelerometer sensor itself vary greatly from one mobile device to the next. Maximum measured speed will be limited to the capabilities of the accelerometer sensor on your device. WARNING!Do not actually throw your phone! No phone throwing is necessary.