Yesterday, Apple iOS 8.3 was released. The list of new features and improvements was long, but now only complain about problems with touch user ID on the App Store.
The users report that the touch-ID support was almost completely removed from the App Store. With each purchase will be prompted for the password, the option to pay by fingerprint is no longer available.
The problem is reported by many iOS devices, including iPhone 5s, iPhone 6, iPhone 6 Plus and iPad Air 2. Maybe Apple is already here need to top up a minor update in the form of iOS 8.3.1 soon.
For problems that are not caused by iOS 8.3, we here offer solutions: Touch ID does not work? Troubleshooting iPhone fingerprint sensor.(via Reddit)