With Fedilab, which I mainly use for Mastodon, I browse peertube and if I'm logged out of lemmy/kbin I happen to like posts from that account, on mobile I find it difficult to use multiple apps. I find that app has pretty complete support to most fediverse sites
Some things that haven't been proposed here might be to use it as a nas. If you want to access your films and shows from outside it's easier to set up Plex instead of jellyfin for now. You can use it also as a steam machine streaming from the pc to the tv, or as Kodi/Libreelec mediacenter to make your tv smart
I am not good with coding, I know the basics, and I use copilot or chatgpt to generate simple scripts to do guis or automate things, and usually works first or second try