EMF Detector is a mobile application that detects and measures electromagnetic fields (EMF) in the user's environment. The app uses the device's built-in magnetic sensor to detect and display the strength of EMF in the form of a numerical reading, as well as a visual representation on a gauge. Users can also use the app to detect EMF sources, such as cell phones, WiFi routers, and other electronic devices. The app may also include features such as logging and charting of EMF readings over time, and alerts for high EMF levels.