Nescaline’s run at the App Store was short. According to MobileCrunch, the app rose and fell within 24 hours. Nescaline was the first Apple-approved commercial Nintendo Entertainment System emulator, and likely the last. Apple don’t ‘do’ machine emulators; not unless they can control each app’s content distribution and safely skirt patent issues. Nescaline does not, did not, and likely will not meet those restrictions and for that reason, was removed from the App Store. In the meantime, it has generated a bit of a buzz. Though it came without official NES games, users were able to point the app to an official app in order to play it and therefore, install copyrighted games. The good thing for gamers is that Apple’s slip ups have brought an official NES emulator for the handful of early downloaders. The bad news is that it is back out of the App Store. And Nintendo are not likely to relinquish rights to games which use its patents, especially with the iDevice hot on its heels.
You can find out all about the now-defunct Nescaline by visiting dev zdziarski’s webpage.