Apple iOS 6.1 Beta 4 for iPhone 4 GSM (Rev A)
Posted: December 17, 2012
iOS 6.1 beta 4 can be installed using over the air software update from devices that have iOS 6.1 beta 3 installed. Over the air software update can be initiated by choosing General - Software Update in Settings.
Be sure to backup your devices using iTunes 10.7 or later through iCloud backup prior to installing iOS 6.1 beta. After installing iOS 6.1 beta 4, you can restore your device using either iTunes 10.7 or later through your iCloud backup.
IMPORTANT: This version of iOS is intended only for installation on development devices registered with Apple's Developer Program. Attempting to install this version of iOS in an unauthorized manner could put your device in an unusable state.