Lie detector: test is a real truth detector app, also known as a polygraph test. Indeed, it allows you to tell if someone is lying or telling the truth. To use the lie scanner: Cover the back camera with your finger and say something. The app will scan your fingerprint and understand if what you say is a lie or a truth. The lie detector will measure your pulse and give you a result based on the variation of your pulse. It is a true mind reader. This lie detector works like a true polygraph test, indeed like a real test it can detect your heartbeat in your finger. It measures and records your pulse while a person is asked and answers a series of questions. For a good laugh, prank your friends, use the truth detector on your family members or friends. Disclaimer: Use for entertainment purposes only, the app does not provide real truth detection functionality.