Info: Not all android devices have a built-in magnetometer, so please be advised that it may not work with your device. Icon and text will indicate if device is compatible once application starts. Accuracy is dependent on manufacturer. A magnetic field sensor (also known as magnetometer) reports the ambient magnetic field, as measured along the three sensor axes. The measurement is reported in the x, y, and z fields and all values are in micro-Tesla (uT). Settings: For audible alarm and vibration on high field detection click on respective buttons to toggle. Change alarm sensitivity by clicking on reading and swipe seek bar to set. Calibration: If output readings fail it attempt to calibrate by gently shaking the device or waving the device in a figure 8 pattern. Permissions: Vibration: select whether device should vibrate when high signal is detected. Wake lock: Device will not sleep during operation.