? ROM (range of motion) measurement   goniometry   Electronic goniometer   Electronic Protractor? E can be used as a protractor.? physical therapists, doctors, etc. who need to measure the angle of the joints can be useful for people.? Application for range of motion is measured.  For mobile phones using the sensor to measure because it requires attention. For more information, please see the Help within the application.? start button, click, click, and then when the stop button to display the angle.   Note) have a cell phone, a vertical position should not be included in the measurement range.? Please refer to my blog (simple user guide).? ^ ^ Please email any questions