TinyUmbrella lets you update iPhone 4 to iOS 4.2.1 while preserving its baseband 01.59.00 which is unlockable with UltraSn0w. In this guide, you’ll learn how to update iPhone 4 to iOS 4.2.1 firmware while preserving baseband 01.59.00 using TinyUmbrella.
In this guide you’ll learn how to update iPhone 4 to iOS 4.1 without updating baseband 01.59.00 which is unlockable.
UltraSn0w 1.0-1 is out to unlock for iPhone 4. This guide is on how to unlock iPhone 4 with UltraSn0w on iOS 4.0.1/4.0 baseband 01.59.00. iPhone 4 unlock instructions can be found below.