My app is a prototype in the sense that I want more features, but the app has just enough functionality that I lack motivation to implement more features. Currently has audio playback, remote file access, and FLAC metadata parsing. Similar to the author, I originally wanted to use React Native because I have experience with it and already maintain a few React Native applications. However, I am not interested in targetting (or debugging) other platforms. So I decided to try using SwiftUI and used a special tool[1] to get something resembling hot reloading. (It's kind of a gross hack that requires supplying custom linker flags in Xcode, but it works just enough for me to not miss the DX of TypeScript and React Native).
Actually, I think it is a bit odd that the author didn’t find a free music app they liked. But I also think you don’t really need an excuse to go make something anyway, so… I dunno, it think maybe that was just a framing narrative to get the story started.