A free program for Android, by Knowledge Quiz Games.

If you like pranking your friends and family, you better hold your horses because we may just have the best tool to pull pranks with.

The Ghost Detector – Radar Prank is a great way to trick your friends and family who get scared easily. It lets you pull some tricks by scanning the place and showing high make-believe frequencies and magnetic fields. The only thing you need to do is act as if there is a ghost around.

Note that this tool is for pranking only and does not actually detect ghosts and other paranormal stuff.

This is available on the Google Play Store.