Why do you need them to have an account? What on your roadmap requires it? And perhaps you could leverage Game Center accounts for "play" data, which leverages

Why do you need them to have an account? What on your roadmap requires it? And perhaps you could leverage Game Center accounts for "play" data, which leverages Apple's sensitivity to provide privacy while allowing achievements, multiplayer, and turn-based games, between partners. https://developer.apple.com/game-center/ https://developer.apple.com/game-center/