I think federated software should probably be focusing on a web-first rather than app-first approach. That has to include an excellent mobile web experience, which Lemmy could use a bit of work on (the software is fairly young and this is not meant as criticism). Mainstream users do have an app-first habit right now. I don't think that's necessarily because people prefer apps to websites, but because companies are pushing apps and deprecating websites. I've read that app users are, on average seven times more profitable than web users.

It's easy to figure out how and where to sign up when you're linked to https://lemmy.fmhy.ml/. When inviting people to Lemmy, it's probably good to just directly link a server.