Drop a tune. A little dancer listens to it first, then dances to it: on the beat, bigger when it gets loud, singing along when there is a voice. Nothing leaves your device, and the video exports straight to a file.
The dancer reads the whole tune before it starts, so it can wind up ahead of a beat and land on it. If the tempo comes out wrong, halve it, double it, type it, or tap it. A voice file is matched to the tune from its start, drives the mouth, and switches the dancer into singing whenever it is speaking; leave "play it too" off when your tune already has the voice in it. The routine is yours to edit: the timeline shows what each arm, the head and the body are doing bar by bar. Every bar starts on auto, and the moment you change one it becomes yours and stops re-rolling; the dials above reshape the whole performance without touching a single bar.