You might want to check out Bricolage (https://appsto.re/us/0bqY2.i
). You're right that there's no motion graphics editor like After Effects on iOS (yet), but Bricolage does allow for some highly complex compositing. It's a node-based compositor/effects-editor, and it doesn't have a timeline, so you have to prep any video assets to hit the times you want before bringing them into Bricolage, but it does have some compelling features. It has a surprisingly clean chromakeyer (IAP), and I've layered six different video elements and a bunch of still elements in some shots.
I think that LumaFusion and Bricolage use the same core effects engine built in to iOS, but their interfaces couldn't be more different. Each has its strengths, and there are some pretty amazing things you can do with them both.
You also might want to look at Animation Pro (https://appsto.re/us/iXDEbb.i
), which is a character animation app that would allow you to do the vector-like squash-and-stretch of shapes in your headphone icon. Once rendered from Animation Pro, you could bring that animation into LumaFusion or Bricolage and do further compositing and sweetening.
This was a great video, though, showing how much you can accomplish on an iOS device!