Hell, I use the (closed-source) app Smart Audiobook Player and I wanted Audiobookshelf integration. I asked Claude, it decompiled the app, added the extra code, recompiled the APK and it works perfectly, syncing my book's progress with the server.
I could write something, but it would be "I told Claude to do this and it did, I'm happy", there isn't really much more detail to write about. What would you like to see?
Truly magical, it would have taken me months.