Everything you need to know about GreenReadr.
GreenReadr uses the precision accelerometer and gyroscope built into your iPhone to measure the slope of the green surface. Simply place your phone flat on the green, and the app calculates the angle and direction of the slope, showing you the break visually on screen.
Under the Rules of Golf, the use of slope-measuring devices is generally not permitted during competitive rounds unless a Local Rule allows it. GreenReadr is ideal for practice rounds, casual play, and training your eye to read greens better. Always check with your competition committee regarding device rules before using in a tournament.
No. When placed gently, your phone's smooth flat surface does not damage the green. We recommend placing it carefully and avoiding dropping it onto the surface. Treat it the same as placing a ball marker — gently and with respect for the playing surface.
No. GreenReadr works entirely offline using your phone's built-in sensors. No Wi-Fi, mobile data, or GPS is required. It works anywhere — even courses with no signal.
GreenReadr supports any iPhone running iOS 16 or later. The sensors required for slope measurement are present in all modern iPhone models.
GreenReadr reads the slope at the point where you place your phone. Modern iPhone sensors are extremely precise for tilt measurement. For the best results, ensure your phone case has a flat back surface and place the phone on a smooth area of the green.
No. GreenReadr does not collect, store, or transmit any personal data. The app operates entirely on-device. Please see our Privacy Policy for full details.
Visit our Support page to send us a message. We aim to respond to all enquiries within 48 hours.