New version supports iPhone 3GS, iPhone 4 and iPod Touch 4G. It does not work with A5/A6 devices, like iPad 2, iPad 3, iPhone 4S, iPhone 5, etc. Sn0wbreeze can be used to create a custom firmware with jailbreak and preserve iPhone modem (baseband) version for unlock. It can also be used to upgrade iPhone 3GS modem version to 06.15. If you don't need cellular unlock use Evasion utility, tutorials are available here. Sn0wBreeze 2.9.10 released: custom firmware and jailbreak for iOS 6.1.2.
IMEI Unlock doesn’t required specific iOS cause any iOS will work on any iPhone Type [ 7 Plus, 7, SE, iPhone 6S Plus, iPhone 6S, 6 plus, 6, 5S, 5C, 5, 4S, 4, 3GS, 3G ].