Enlarge / That is in no way what the Z button looks like or where it goes... Apple's decision earlier this month to open the iOS App Store to generic retro game emulators is already bearing fruit. Delta launched Wednesday as one of the first officially approved iOS apps to emulate Nintendo consoles from the NES through the N64 and the Game Boy through the Nintendo DS (though unofficial options have snuck through in the past). Delta is an outgrowth of developer Riley Testut's earlier sideloadable GBA4iOS project, which recently had its own unauthorized clone removed from the App Store.