A new face tracking algorithm, and a human-computer interaction technique based on this algorithm, are proposed for use on mobile devices. The face tracking algorithm considers the limitations of mobile use case - constrained computational resources and varying environmental conditions. The solution is based on color comparisons and works on images gathered from the front camera of a device. The face tracking system generates 2D face position as an output that can be used for controlling different applications. Two of such applications are also presented in this work; the first example uses face position to determine the viewpoint, and the second example enables an intuitive way of browsing large images. © 2009 IEEE.