Apple has already released a maintenance update only a week following the company’s release of iOS 8. Listed as “containing improvements and bug fixes,” iOS 8.0.1 notably addresses the issue that affected use of HealthKit by third-party apps revealed last week. Other improvements and fixes include issues with third-party keyboards, apps accessing the Photo Library, reliability of the Reachability feature on the iPhone 6, fixes for unexpected cellular data usage when receiving SMS/MMS messages, and more. The update is now available in Settings, General, Software Update.
Update: iPhone 6 and iPhone 6 Plus users have reported a complete loss of cellular connectivity and Touch ID functionality following the 8.0.1 update. iPhone 5s and other iPhone users appear to be unaffected, but we would advise users to hold off on this update for the time being.
Update 2: Apple has pulled the iOS 8.0.1 update following widespread reports of iPhone 6 and iPhone 6 Plus problems.