Music on Vine - Vine, now with music. Make 6-second music videos.
Photomosh - Turn anything into a vaporwave
Mindie - 10 second music videos (w/ private mindies)
HearSeeParty - Combine Gifs with with music using tags
Triller - Make celebrity-quality videos with a few taps of your phone
Decim8 - Turn photographs into glitch art