Stop playing with iOS7 and check out LetsDance.to. It synchronizes music and dance videos to give you endless pleasure by juxtaposing the music from one video with the dancing of another. Synchronization is aided by The Echo Nest API. It is really fun. Check out this strange and mystical dance to Lorde’s Royals.
Music Machinery 
#1 by Andrew Darwitan on November 2, 2013 - 8:39 am
This is really interesting. Not only that we get to choose the permutation between different songs and dancing videos, but we also get to pause the music and see if the music and dancing can be synchronized in different ways. Thanks for sharing!!