For the last few years, I've been building Live Music Archive for iOS (https://livemusicarchive.app), a player for the giant collection of free live music on archive.org because the other apps out there didn't provide the experience I wanted.

I love working on it and wish I could make a living on it, but the nature of the app means I can't pursue commercial gains from it. It's the only side project of mine that I actually use all the time and it has gained a small fanbase, but really, I'm building it for me.