3D Face Scan
Scanned with trimensional.com on my telephone. The future is here.
I've wondered about a few ways smartphones could be used to capture 3D images (e.g. capture frames while swinging phone around object, using motion sensors to record relative location). This app projects different light patterns (bright left/right/top/bottom of screen) on a static scene, so I guess it is a structured light approach. So comparison of a pixel's brightness under each illumination condition allows estimation of the location of the surface at that pixel, given illumination from different angles.