Android sensors - accelerometer and magnetometer
In addition to understand concepts of accelerations and orientations (azimuth/pitch/roll), there are 2 practical dumb usages: Leveling tool: lay your phone flat on a surface, if the surface is perfectly leveled, you should have reading of X and Y to be 0, and Z to be 9.8; Compass: lay your phone on a surface, top edge of your phone (Y axis) is pointing to Magnetic North when the reading of Azimuth is 0.
To install, download APK from https://github.com/sproffer/SensorTest/releases/download/packaged/sensorTest.apk
![Screenshot](https://img.garyzhu.net/img/SensorTestScreen.png)