In this chapter, we covered in detail how to get started with HealthKit. We explained the idea of the HealthKit framework, and how to deal with sensitive data. We mentioned the HealthKit limitations, and its availability in the iOS devices. We saw how the users' data is protected in the Health app, and any app that needs to access or share any data type will need permission from user. The user can enable or disable this permission anytime from the Health app. We also learned how to read and share the data to the Health store, and how to deal with units. In the next chapter, we will give a good introduction, and the basic information that is needed to get started with Metal. Metal is a new framework for the GPU-accelerated 3D graphics in iOS.