There’s one Android nostr app (Amethyst) that has implemented an edit feature, but it’s not supported by any other app I’m aware of so even if you edited a post there, every other app would still show the original. So essentially, no edits.

There is support for “delete” within the nostr protocol, but not every app or relay has implemented it. Since it’s decentralized, there’s no way to ensure it’s truly deleted everywhere, so that’s why some app teams have chosen to not give the option at all. My experience has been that it actually works fairly well in apps that give the option. On iOS, neither Primal nor Damus gives the option, but Nostur (another app) does.