Measure angles with precision:1- "set 0º" to establish a relative 0º2- rotate device to desired angle and "get reading"Reset and start a new measurement.Precision designed for you. In-house tests have shown tolerances of +-0.2° and +-0.3° depending on device.G-pro gives you quick, repeatable and precise angle readings.G-pro can provide easy and accurate range of motion (ROM) readings. It is very useful for Physical Therapists and Chiropractors in helping assess treatment efficacy. And for initial consultations, re-evaluations, and day to day office visits providing patients a way to see their progress.Use G-pro in radiology in x-ray interpretations (e.g. to determine the degree of scoliosis).G-pro has been designed in collaboration with health care providers (HCP) in an effort to develop an easy to use and reliable ROM measuring tool, a better goniometer app. It has been successfully tested in orthopedic, chiropractic, and physical therapy practices. And can also be used for sports medicine, rehabilitation, radiology, cycling, engineering, architecture and more.G-pro works like a digital gravity inclinometer. Using your device accelerometer chip to calculate the angle of rotation.