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
I guess they try to match the quality of the cesspool that is their comment section