abcde - A Better CD Encoder

Is this the one? https://zellij.dev/about/

I just read that navidrome

Handles large libraries!

Plays well with gigantic music collections (tested with ~900K songs - 2/3 FLAC, 1/3 MP3)

Though, I don’t know if any of the supported Subsonic API clients can handle as much…

being able to control the player from an android phone was so convenient and I don’t know any other player that has similar.

Well, you can remote control playback in Kodi through apps like Kore, and browse the libraries, but it’s a totally different experience in comparison to dedicated music player apps. Kodi is more like software for a home theater PC, a.k.a. media center.

The best viable solution I can think of, that includes a desktop UI and remote control from a phone, would be hosting a Jellyfin server for the music library, then using the client app for Android to remotely control another client app running on your desktop. I do that everyday (but mostly for video content), since I’m using my phone to control playback on a Raspberry Pi running Kodi with the “Jellycon” client add-on, but that could be any other Jellyfin client, such as a regular Jellyfin desktop client.