It’s called Kodi. It’s a media centre that organizes and displays a library of your own, locally stored (on a NAS or external hard drive) video files.

It can be extended with add-ons for example for watching YouTube, but of course there are also some piracy add-ons, which Kodi itself doesn’t condone, but can’t do anything against

Wait, that site is still online? I thought I read they shut down some years ago. Time to check out some old memes I guess