Mega Detector - Metal & Magnet detector, works on all devices and no special sensor needed. A powerful tool to detect metals, magnets and electrical flux. It detects and measures field values using in-built sensor. It use a sensor your phone use for GPS, but not necessary to activate the GPS on your phone.Accuracy of this app depends on the sensors installed in your device and for best result remove phone cover. This APP can't detect gold, silver and coins made by copper. If the value is 0 then the app is not working, the basic value is 30-40 this is the earth magnetic field.