Update: Many users are reporting that cellular functions and Touch ID are no longer working post update, so we would recommend holding off until further notice. Many who have updated their iPhone 4S, iPhone 5, and iPhone 5s are reporting no problems, so it appears this problem is likely confined to iPhone 6 and 6 Plus.
Update 2: The update has been pulled. Apple has issued a statement to Re/code:
Apple has released iOS 8.0.1 to the public, and it’s rolling out now OTA to all devices capable of running iOS 8. The update’s build number is 12A402, and it packs fixes for a variety of bugs that have plagued users of version 8.0. Most notably, the new version includes a fix for the bug that was keeping HealthKit apps from the App Store. Furthermore, the update addresses a plethora of other problems including an issue with apps accessing photos from the Photo Library, a bug involving 3rd party keyboards, an issue that caused unexpected data usage when receiving SMS and MMS messages, an issue involving ringtones not being restored by iCloud, and more.
The update also packs a variety of improvements for already-existing features. According to the release notes, the new Reachability feature should have improved reliability, and there is also better support for Family Sharing Ask To Buy for in-app purchases. This update comes just one week following the initial release of iOS 8, and like that version, the update will work with iPhone 4S or later, iPad 2 or later, both models of the iPad mini, and the 5th generation iPod touch. The full release notes are below.
This release contains improvements and bug fixes, including:
• Fixes a bug so HealthKit apps can now be made available on the App Store • Addresses an issue where 3rd party keyboards could become deselected when a user enters their passcode • Fixes an issue that prevented some apps from accessing photos from the Photo Library • Improves the reliability of the Reachability feature on iPhone 6 and iPhone 6 Plus • Fixes an issue that could cause unexpected cellular data usage when receiving SMS/MMS messages • Better support of Ask To Buy for Family Sharing for In-App Purchases • Fixes an issue where ringtones were sometimes not restored from iCloud backups • Fixes a bug that prevented uploading photos and videos from Safari