Comment by LocalH
The NES itself contains no code. Any NES emulator that ships with no software, or software under proper license (such as homebrew) is unambiguously legal. Does your PC, and the OS that drives it, suddenly become inherently illegal if you, as a user, installed pirated software? No, of course not.
Absolutely! It’s completely, unambiguously legal, which is why Google allows emulators on the Play Store.
Apple, beholden to copyright interests, is wary of software that allows even the possibility of copyright infringement. They just recently allowed video game emulators on their store.
It’s not a legal distinction, sure, but it’s also not apples to apples.