In this chapter, you learned how to take pictures using the camera or the camera roll using UIImagePickerController. We were able to edit the taken picture using a custom view, which contains an array of elements. These elements were drawn using Core Graphics, which basically creates a context. Each call fills it with the corresponding function.
In the end, we were able to retrieve the edited picture and post it on Facebook, allowing us to share the final result with our friends.
In the next chapter, you are going to learn how to control your home devices using HomeKit.