The Gevey Ultra S GSM SIM interposer, which allows users to unlock their iPhone 4S handset, is compatible with Apple’s recently released iOS 5.1.1.

Though a software unlock for the iPhone 4S still hasn’t been developed, hardware unlocks – like Gevey SIM – allow users to apply a carrier unlock to their handset quickly and easily, but for a price ($39.99). However, while some might have worried that updating to iOS 5.1.1 would disrupt the SIM interposer, in a Twitter update published recently, ApplenBerry assures its users that the new software version is nothing to worry about.

Here’s the tweet:

If you’re interested in unlocking an iPhone 4S (currently GSM only) via this method, visit ApplenBerry’s online store, where the Ultra S is available for $39.99.