FaceBoof! is 90% GLSL shaders bundled in a collection of Quartz Composer patches wrapped in a Cocoa desktop application for the Mac. I was looking for something fun to create in order to experience the joys/frustrations of distributing Mac apps through the Apple Mac App Store. Trying to get FaceBoof! ready for the launch of the Mac App Store lead directly to the creation of Tighten Pro.
FaceBoof! includes face tracking (feature detection). The face rectangle is passed, along with patch-specific parameters, into embedded Quartz Compser "image filters" (layered up to 3 deep). Kind of like Photo Booth on LSD.
FaceBoof! on the Mac App Store