GPP Team from Japan has released a sim interposer like Gevey Sim which can Unlock iPhone 4S running on a locked carrier like AT&T . Using GPP Sim you can use any carrier of your choice without jailbreaking the iPhone 4S . It is a one-step plug and play solution that can unlock iPhone 4S on iOS 5.0.1 and iOS 5.1 (at the time of writing this article).
GPP Sim Features :
- GPP Sim does not require jailbreaking and hence the warranty is intact .
- Does not require 112 emergency number dialing
- There is no need to unlock again after losing signal or after switching your phone to airplane mode
- Provides stable EDGE and 3G service
- Supports MMS
- Supports Baseband 1.0.11 , 1.0.13 and 1.0.14
- Turn off iPhone 4S and insert GPP Sim with your microsim card using the provided sim tray inside the iphone sim slot (as shown in the image below)
- Turn on your iPhone 4S and wait for few seconds for the signal to show
- Your iPhone 4S is now unlocked .
You can buy genuine GPP Sim from Amazon . GPP Sim unlocks AT&T USa and Japan’s KDDI and Softbank .
Read in Forum : GPP Sim Not Working Problem
Update : More iPhone Unlock Solution