Sort of a self-hosted Youtube work-alike for your media collection. Browse, organize, and curate your stuff. Movies, shows, music. Live TV enabled, can function as a DVR.
Client apps for Android TV, FireTV, Roku, Kodi, Xbox One, PS4, and more. Or you can watch stuff in your web browser.
Official package repos for Debian and Ubuntu. In the AUR. There's even a portable version (if you have the .net core runtime handy).