This app is primarily used to measure magnetic field strength all around. It could also be used as a metal detector. This app contains the following features:1) The magnetic field measured by this app is the total magnetic field in the device's vicinity without device bias (Earth's magnetic field plus surrounding fields, without device bias).2) Plot the measured data in real time.3) Multiple units supported: nT, T, mT, mG and G.4) Measurement duration and measurement frequency are customizable.5) Users could set alert value to some level (Ex. 120 T). When the measured magnetic field exceeds the alert value, it will alert users.6) The location information of the measurement points could also be obtained, and all the measurement points could be shown in map.7) All measured data could be exported as a csv format file for post process.8) In addition, users could also add photos, videos and voice records to the measured data, and the photos, videos and voice records could be downloaded through iTunes.