A free program for Android, by Apptocker.

Spy Cam-Hidden Camera Detector is a great security and privacy app that helps you find and capture any hidden cameras or other security devices that may be around you. This tool will scan your phone for any magnetic activity, which may be a sign of a camera or other security device. If this is the case, you will be notified and the application will start beeping.

The best part of this tool is that it works on your phone. You don’t need to download anything. The app is built-in the phone and works right away. You don’t need to turn on your phone. It works even when you are asleep. This is a great tool to use in your bedroom or anywhere else you might think there could be a hidden camera.