Metal Sniffer is a free, easy-to-use metal detector application that leverages your Android phone's built-in magnetometer/compass to detect nearby electromagnetic fields. The app is developed by Yu Chen Hou and falls under the category of Utilities & Tools. With Metal Sniffer, you can locate nearby metal and magnets, find metallic studs and wiring behind walls, and detect hidden electrical wires.

The app displays the x, y, z components of the magnetic field in the unit of your choice (Tesla, Gauss, or Gamma), and combines them to give a scalar reading. You can set a threshold at which the phone will vibrate when a critical reading has been reached. The app also features a compass-like arrow that points out the direction of the source of the magnetic field.

Metal Sniffer is optimized for Ice Cream Sandwich/Holo theme and offers four sensor speeds and three different units. You can also export the data to a CSV file, make cool charts, and record readings for tracking or research. The app also has a historical chart, and vibration alarm. It is available in Russian, Spanish and Dutch translations.

Metal Sniffer works on Android 2.1 and up and is a fun and useful tool for detecting metals and magnets around you.