I agree with Karnage, is a really full featured client with a lot of nice stuff, by seems lacking a proper UI/UX planning.
A UX/security suggestion: if you ask the user to write down the wallet seed check it in the next step asking him to insert it again to verify the backup. It is a little tedius process (even if can speed up with a clever interface) but a necessary one, don't trust the user's lazynes, can cost you a lot of bad reviews because he lost all his sats after a phone crash o an app update goes wrong.
Because this is first of all a Nostr client and the user want to see some content asap, I suggest you to posticipate the wallet creation in a later step.
Then I will not let the the user choose a tld for the username; there isn't a real advantage, slows down the process ("which one I should choose?"), creates confusion when searching other users and worsens the perception of the brand (your nickname here is getcurrent_IO!).
Btw, nice work! :)