Either, that's the beauty! Or I hope so, been using about every app this week.
Discussion
Ok so it doesn’t matter
Nope, that's one of the reasons it's resistant to censorship. One app gets taken down, another pops up and you just keep your nsec safe and log right back in a different app. The relays(where all your info is stored) is the other part, but that is mostly backend stuff you shouldn't have to worry about. It's a bit overwhelming for a lot of people coming from a login/password world, but you seem to be getting the hang of it. You got this 👊