I was an Invidious user until I found out about Libretube, and the fact that on Libretube and even on a Piped website you can login to get your subs from other instances. That is crazy useful.
There was a momentary bug, but it was fixed quickly. I recommend not using the F-droid repo, because new releases take days and days to arrive, rather use Izzy-on-droid if possible.
Invidious vs Piped. Which is better?
How do these work?