This application suggests how to hit a putter by entering various conditions such as the slope of the green, speed, and putt distance. The application performs an approximate calculation by assuming that the putter stroke is a pendulum motion and the motion of the golf ball is a frictional motion as it rolls down the slope. Based on the results of the calculation, it suggests the direction to hit with the putter and the width of the swing, and displays the balls roll as a trajectory. While it will not always give you the correct answer for the hole, it will help you learn the tendencies and characteristics of your putts. Use the app to gain analytical experience and multiply it with your playing experience to improve your golf score.