Download App Lock Apk: Fingerprint Password Unlock Your App with your Fingerprint. We all know the moment of discomfort when handing a phone to friends or family, only to see them suddenly start opening applications that are personal to you or have sensitive information. That's why we built a secure and easy-to-use application locker with PIN, pattern or fingerprint password protection, so you can hand your phone to other people without worrying that they will stumble into the wrong application or screen.