Health is an application for iOS 8 and iOS 9 announced by Apple Inc. at their Worldwide Developers Conference (WWDC) 2014.
The application is intended to be a personal and central data collection point, for connected third-party electronic accessories and wearable technology, that can directly monitor and analyse an individual's biochemistry and physiology for medical and general fitness purposes.
It displays a dashboard of all the fitness and health data of the user, including the heart rate, calories burned, blood pressure, blood sugar, cholesterol, and other similar functions. Users can also use the Health app to create a Medical ID, an emergency card with important medical details and emergency details. The Medical ID is accessible from within the Health app or from the lock screen
Although the application is available in iOS 8 and iOS 9, it is currently only available on iPhone and iPod Touch, but not on iPad.
HealthKit is the accompanying developer application programming interface (API) included in the iOS SDK (Software Development Kit) for the Mac. It is used by software developers to design applications that have extensibility and that can interact with the Health application on iOS.