TPP Sim was the first solution that promised to unlock iPhone 4 iOS 4 baseband and also iPhone 4S running iOS 5/5.0.1. This unlock solution was released last week and went on sale at a price of $ 90.
Shortly after appeared PPG SIM, an unlock solution that works only on iPhone 4S coded on U.S. carrier AT&T and Japanese carrier Softbank.
R-SIM, the third unlock solution, works only on iPhone 4S but is not compatible with 3G networks.
So far nobody has been able to confirm that the cards work without problems, but early indications suggest that they were real. Despite the fact that the price of such unlock solution is very high soon they will be available in stores around the world.
Also Applenberry, the GEVEY SIM developers, is testing a new unlock solution but nobody knows when will be available. Finally we have TPSIM, PPG SIM, R-SIM and a possible solution from Gevey, all suggesting that unlock iPhone 4S.