In this chapter, you have learned how to use an Xcode asset catalog to add the required icon images to your watch app and you have used an extension to provide advanced animation functionality to an InterfaceController object beyond that supplied by WatchKit itself. You have learned to lay out the user interface in code as an alternative to using Interface Builder and you have seen how to add media playback to your apps.

Although the techniques presented in this chapter will already elevate your projects to an altogether higher level, giving you opportunities to further engage and delight your users, they are intended as first steps toward a rich and detailed understanding of the wealth of opportunity offered by the Apple Watch. The ways in which we will all be using these features in the not-too-distant future are largely in the hands of you, the developers, whose task it is to explore this wide open field of mobile technology.

In the next chapter, we will look at what needs to be...