jellyfin-audio-player VS Deej-AI

You're welcome! Finamp is very good, then there's also https://github.com/leinelissen/jellyfin-audio-player which is also worth trying.

Fintunes: Streaming audio player for Jellyfin

Check out Fintunes for music! https://github.com/leinelissen/jellyfin-audio-player

jellyfin-audio-player Has a more iOS-centric design

I’d also like to point out Jellyfin Audio Player, which looks far more native on iOS.

Jellyfin Audio Player also exists, but I've not tried it quite as much. It seems to be somewhat inferior to Gelli feature wise, and also doesn't have offline mode. It does have a unique somewhat "iOS-like" interface if that's something your brother would like. It is also installed by sideloading.

Your best shot at this point in time might be trying the unofficial Jellyfin Audio Player.

For automatic playlists that make at least some sense I used https://github.com/teticio/Deej-AI in the past, is not human-level good but the results are enjoyable.

I recently found this Deej-Ai project on github (https://github.com/teticio/Deej-AI), and I think it would be perfect for this use case. The AI can either be Self-hosted (as mentioned in the github page) but there is also a publicly accessible site (https://deej-ai.online/playlist). On this post I'm going to focus on a possible implementation using the site.

This is FAR from a click or two but I have wanted to do something similar. I haven't had the time to dig into this yet but I came across https://github.com/teticio/Deej-AI which is a way to train models based on your personal music library (among other sources). Ideally from this you'd be able to create Jellyfin playlists but using the Jellyfin API: https://api.jellyfin.org/#tag/Playlists