So I've created a shim for iOS. You play a gentle, low sound, not unlike goats bleating. Then you check the accelerometer[1][2] for the unique pattern of sound waves rebounding from the hairs of theuser's beard. (Remember, the iOS accelerometer is amazingly accurate. This technique really works!)

If you're interested, drop me a line at 1.800.GOAT.API and I will license my patent for your app.

[1] Cf. http://stackoverflow.com/questions/13248493/detect-ipad-mini... [2] Also relevant: http://xkcd.com/378/