1. A method for biometric authentication of a user comprising the steps of: a) providing: a mobile device comprising a camera and a screen; and a database; b) superimposing on the screen a translucent overlay of a finger over a real-time image as currently seen through the camera; c) capturing with the camera an image of a fingerprint of the user; d) comparing the captured image with an authenticated fingerprint image that is stored in the database; and e) returning a positive result if the compared images match.