An alternative video client. Mostly known for pulling add free youtube. But you can have several sources like patreon or nebula. The app is free and source available but they ask you to buy a license if you like it. It's made/supportes by futo
Edit: changed "open source" to "source available"
Ah thanks A bit more context would have been nice but anyway
I was not aware of the distinction.
Grayjay is source available. But you are essentially not allowed to do anything with/to it.