provides instant feedback to build muscle memory and consistency between shots. >> technology could help people learn and perfect skills. >> reporter: two former cell phone employees partners to use smartphone sensors to track the movement of your arm. >> there are sensors on the forearm and bicep. >> they sense position and motion in space. from that, we can then model how the arm is moving. >> a buzzing noise indicates poor form. a victory tone signals a good shot. a mobile app provides feedback in how to improve your shooting skills. >> the number one thing is get your arm higher on the shot. >> reporter: coaches and high school players in california are testing the device. >> i would say my shot improved, keeping my elbow in. >> reporter: it could be