The App store has a lot of apps that exaggerate their functionality. Like this one. However, one must take apps as this with a pinch of salt as you download them more out of fun than anything else.
Lie Detector 2.0 by William Stevens is one such application. The application asks you a series of questions and based on your responses, it will decide the probability that you are speaking the truth. This analysis, the developer says, is based on the motions, shaking of hands and face observation. I tried the app and it appears to be offering me the benefit of doubt that I am speaking the truth.
To be fair, analysis of face movement, hands shaking are fine. But for a questionnaire that consists of questions like ‘What’s your first name‘, ‘Where were you born‘,etc. the user does not have to actually tremble while lying.