I was tasked with building a bespoke JavaScript framework for the web last year because that's just what the world needs right? :) Anyway, one of the requirements was that it be similar to building an iOS app so all the views, layouts, and styling needed to be done with code. This would have been really cool to have to jump start some of that work.
P.S. I know there are a bunch of frameworks out there that do the same thing I built. The company I built it for specifically wanted a custom one for themselves. It's decisions like that that led me to leave. Still, fun project and I learned a ton.