No jailbreak was required, although not every game suits touchscreen operation. Apple's predictably closed the door on easy Nintendo emulation on iDevices, at least for now.
If you're a jailbroken iOS user and gamer, then emulators have been available to you for absolutely ages, but within the walled garden of Apple's App Store, they've generally only appeared by stealth, and been pulled relatively rapidly as soon as they were spotted.
This week, for a brief period — sorry, it seems to be over — it was feasible to install the GBA4iOS emulator on a stock iOS device, simply by heading over to GiTHUB on an iOS device and installing from there.
So how did that work, exactly? Don't apps have to be installed from within Apple's own ecosystem?
The answer to that is essentially "not always".
The apps that you get from the App store are all vetted by Apple beforehand, but they also provide facilities for enterprises to roll out their own applications to their iOS devices. That makes sense from an enterprise point of view, because they can sideload confidential data and applications without making their apps widely available, as well as keeping Apple happy, as it doesn't have to test the apps or warrant them as fit for purpose in any way, while keeping enterprise companies on board.
One of them, MacBuildServer, was a web-based interface for this kind of operation, but its adherence to the rules when it came to granting certficates was, shall we say, a little on the lax side. In essence, it was allowing any code to pass through it for "testing" purposes, including the GBA4iOS app. It appears that Apple's wised up in this case; as ReadWrite reports, trying the install trick now on an iOS device simply leaves you with an error message and no emulator. Theoretically if somebody wanted to risk the licensing fee for Apple's Enterprise Developer program, the same loophole remains, but I suspect it's something Apple will be a little more vigilant about in the future.
Any emulator is worthless without games, but as I've covered over at Lifehacker previously, you're actually not allowed to run backup copies of games under Australian copyright law; technically the code is OK to backup, but the associated assets, such as art, music, visuals and so on are explicitly excluded from the format shifting rules.
Apple Slams The Door On Super Mario [ReadWrite]