Would love to see an option to switch between light and dark theme and highlighting few things with different colors.
Neither of us is particularly good at UI/UX stuff, but we can give it a shot! :)
Maybe a similar project for descriptors with options to experiment with descriptors would also be useful.
I don't think this is exactly what you have in mind, but a while back I made a web-based tool to build descriptors graphically, based on Scratch. You can find it here, on BDK's website.