Apple has released the own sample, available from GLCameraRipple and this is not the end of the story: some guys have decided to sell the sample and more - it has been accepted by Apple and App Store, just here - Ripple HD
(verified by shaders :) - 100% the same, including "Copyright (C) 2011 Apple Inc. All Rights Reserved." )
PS if you are interested in "how to implement?" - just look for the full sources at the sample page from Apple, YUV -> RGB is there and more, like simulation of UVs via
runSimulation and rippleTexCoords
Nothing to say more from the technical side of the Ripple Effect implementation question.