MPD client I use on my tablet. It's no longer being developed, but it works fine. On my phone, which is Android 13, it's a little buggy, and most annoyingly doesn't set me set individual settings per network, but is usable.
If you have an Android version newer than 4.4 you might have a better time with MALP, or one of the ones on the Play Store I haven't tried.
Apparently this fork is able to be built on modern systems: https://github.com/hurzl/dmix
I can't get cover art to work. You're supposed to be able to use the cover.jpg (or whatever) files you have in your album directories if you run a web server, but I've had no luck doing getting it to find them on my NAS. Tried adding the directory to the Apache config, tried a symlink…I don't really care enough about seeing the covers to fuss with it any further.
There's a separate area for saving radio streams, these are stored in a playlist in your MPD playlist directory called [Radio Streams].m3u in the format [URL]#[Stream name].