In this paper, we study a recent biometric modality for user authentication on mobile devices. The proposed solution is a two-factor user authentication scheme and gives some high guarantees on user's identity. We first use the knowledge of user's password represented by a secret path on a grid composed of 9 points. Second, the behavior of the user while giving its path is analyzed to verify its identity. This solution is implemented as an Android application for mobile devices. Experimental results on an own made biometric database show promising results.