HealthKit powers a corresponding app called, simply, Health. The app, which comes with iOS 8, shows data about your activity levels, blood pressure, calorie burn, and sleep activity from your health and fitness devices.
You can get detailed reports on your health in the Health app, and create a wellness plan to stay in shape and eat well.
Nike is one of the first partners for HealthKit.
Apple didn't expand onstage at WWDC on exactly which fitness and gadgets will plug into HealthKit, but we anticipate that the Fitbit, shown above, will be one of them. Stay tuned to CNET for more information about HealthKit.
Apple is partnering with the Mayo Clinic to assist you with your health needs. If the Health app tells you that your blood pressure or other metrics aren't healthy, it'll help connect you with a doctor to get care.