The comments on https://news.ycombinator.com/item?id=38718544 are proof that we can't make "just apps" and have people use them without knowing that Nostr is a thing. Users must know.
And in fact I think it is much easier to teach people about Nostr than about why your damn app doesn't have email+password login and where is it storing things and how does moderation work without telling them about Nostr.
And when they finally understand the basics of Nostr they will suddenly understand everything about not only your app, but about all other Nostr clients.
Proof for this is to go to yabu.me and despite not knowing a word of Japanese, still being able to post and interact because you already know - as memory reflex - how nostr conventions works (nip-07, lists of relays, the + button, etc.)
Nostr in this sense is alike transit etiquette (following transit sings in other country), or if you like, like driving standard (whereas x is the puny automatic or self driving 😆 )
