It’s super nice. It used to be locked behind a paywall (I paid for a Plex Lifetime pass years ago because I have used it for ages) but I think Plexamp is free now. Otherwise I hear Jellyfin is a good alternative with a bunch of good music player apps.

If you don't mind a one time cost on android symfonium is a great app to stream self hosted music I find it a bit limiting on Plexamp due to a lot of useful features being behind its paywall despite maintaining basic core features