There are some limitations that everybody needs to be aware of before deciding to work with HealthKit:
- The HealthKit framework is introduced in iOS 8.
- HealthKit and the Health app are not available for iPad.
- The HealthKit framework can't be used in the app extensions, such as WatchKit.
- You need permission to access every type of data in the Health app. For example, a user can let your app read the blood type info, and prevent it from reading the heart rate or the step count info.
- The HealthKit store is encrypted, and your app can't read data when the phone is locked. So, when your app runs in background, it may not be able to access the store. However, your app can still write data even if the phone is locked, as the data will ...