Apple today stopped signing iOS 9.3.3, effectively ending user’s ability to either upgrade or downgrade to that version of iOS. Apple also today stopped signing iOS 9.3.2.
iOS 9.3.3 Stories August 24, 2016
iOS 9.3.3 Stories May 23, 2016
Apple has released a new iOS 9.3.3 Developer Beta 1 for developer testing on iPhone, iPad, and iPod touch. The update weighs in around 1.4GB and is available over-the-air for devices registered to test pre-release versions of iOS.