Apple has released iOS 8.0.1, an update that brings several bug fixes to iOS 8, which was released last week. However, you need to be careful if you upgrade.
The upgrade fixes an issue with HealthKit that prevented apps that support HealthKit from being allowed in the Apple App Store. According to Apple, iOS 8.0.1 also:
° 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 the 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.
You can download the update from the Software Update section of the iOS 8 Settings application.
Updating to iOS 8.0.1 has killed the cell service on some iPhones, it seems. According to MacRumors.com, several users are reporting “No Service” messages after updating. Affected users also appear to be experiencing problems with Touch ID, which seems to be completely non-functional.
MacRumors says it appears that the issue is limited to users who have an iPhone 6 or an iPhone 6 Plus, but affected devices span several carriers, including AT&T, T-Mobile, Verizon, and Sprint in the United States. Rogers subscribers in Canada have reported issues, as have EE subscribers in the United Kingdom and Vodafone subscribers in Germany.