It's not exactly a "one-man show," but I'm the chief architect, and the only one developing one of the three servers the app uses (I was also the original architect for another server, that is now being run by a different open-source team), I am also the only one developing the native iOS application. I may be writing some adjunct apps, once the main one has been released (like Watch, Mac and TV apps).
But we're a team. It's a 501(c)(3), with a mission to Serve a specific demographic. We have the advantage of being intimately familiar with the demographic. So far, we haven't had to shell out much. If they decide to write an Android version, then it may take some extra dosh. The good news is, the app is in "constant ship" state, so asking for funding is fairly straightforward. We just need to loop the person into the TestFlight group, and Bjørn Stronginthearm is your uncle.