Up until this point, we’ve written applications with a single view controller. While there certainly is a lot you can do with a single view, the real power of the iOS platform emerges when you can switch out views based on user input. Multiview applications come in several different flavors, but the underlying mechanism is the same, regardless of how the app may appear on the screen. In this chapter, we’re going to focus on the structure of multiview applications and the basics of swapping content views by building our own multiview application from scratch. We will write our own custom controller class that switches between two different content views, establishing a strong foundation for taking advantage of the various multiview controllers that Apple provides.