I am the developper of reel2bits.
It’s a soundcloud-like self-hosted app, which goal is to be kiss and easy to use. And I am currently trying to implement ActivityPub support.
I would really love to have some more contributors than just myself to work better on it. (python3, flask, celery)
A matrix room have been created for that: reel2bits:otter.sh. And I have at least this week and full next one free to help anyone getting on the codebase.