It’s an alternative jellyfin + radarr + sonarr (jellyseer) front end. It’s in very early stages but it looks and feels so good. I read on the issues that work will progress but there needs to be a lot of planning.
Anyway, it looks good! star it and watch out for the next release
If I’m remembering correctly, Jellyseerr is the only one that has integrated account authentication with Jellyfin (which I have using my standard LDAP for accounts).