Just a proof of concept that you can create a player app using kivy.
Unfortunately I had to bring up an additional api to download mp3 files, as I couldn't get ffmpeg to work to convert from .webm to .mp3. But, you can try to build ffmpeg-kit with lame https://github.com/ArqiesAr/FFmpeg-Kit-Python
- Download docker buildozer and build it
git clone https://github.com/kivy/buildozer.git
cd buildozer
docker build --tag=buildozer .
- Build app
docker run --volume "$(pwd)":/home/user/hostcwd --volume "$HOME"/.buildozer:/home/user/.buildozer buildozer android debug