2 games have apparently been authorised and are being sold on the appstore, those games are pokemon yellow and pokemon pocket edition
Pokemon yellow doesnt work, people have reported that the game make the hardware crash
http://www.joystiq.com/2012/02/20/fake-pokemon-yellow-ends-up-on-ios-app-store/Quote
A fraudulent version of the Game Boy Color classic Pokemon Yellow has somehow made it through Apple's approval gauntlet and wound up on the App Store. Published by "Home of Anime" with Daniel Burford listed as the author, the "game" runs for $0.99 and has a one-and-a-half star rating after 1,352 reviews. According to said reviews, the app crashes after the title screen and cannot actually be played.
as for pokemon pocket edition its only a gallery of pokemon screen shotshttp://www.develop-online.net/news/39862/Apple-blunder-as-5-Pokmon-scam-enters-App-StoreQuote
Milanovic’s description of the app reads: “Marking the Pokémon series’ glorious debut on the App Store, Pokémon lets you verse and play as everyone's favorite Pokémon, Pikachu, around awesome lands.”
The app description continues: “using the stylus to control your favourite Pokémon, zip across land and sea—even through the air—on a mad dash for the finish line”.
The scam puts into perspective Apple’s existing publishing guidelines and approval processes. The iPhone company’s general laissez-faire approach to content regulation has led to numerous game clones syphoning revenues from legitimate revenues.