Update your apps to use new features, and test your apps against API changes.
The iOS 12.1 SDK provides support for developing iOS apps for iPhone, iPad, or iPod touch devices running iOS 12.1.2. The SDK comes bundled with Xcode 10.1 available from the Mac App Store. For information on the compatibility requirements for Xcode 10.1, see Xcode Release Notes.
Resolved an issue where some user interface elements were inaccessible to VoiceOver in the “Electrocardiogram (ECG)” and “Irregular Heart Rhythm Notification” sections in Health > Health Data > Heart. (46505168)
Audio performance when using some third-party apps is improved on iPad Pro 12.9-inch (3rd generation) and iPad Pro 11-inch models. (46037111)