I just clicked through and noticed the client-server part. I'd be curious to see if a smaller Whisper model could run on an Android phone too... All the same, nicely done!
As mentioned in the git README (at the bottom) there is at least one Whisper port that runs natively on Android. It does not run as fast on an Android phone as on iPhone (because of whisper.cpp optimizations for Apple silicon) but it still runs pretty well. In my tests, it does not run as fast as sending the raw audio across the network to a fast server for transcript there, which is what this post is about. But give it a try.