View Controllers - iOS Programming: The Big Nerd Ranch Guide - page 219

UIViewController
A UIViewController instance specializes in controlling a single screen within an ap-
plication. Every UIViewController has a view property that points to an instance of
UIView or one of its subclasses, and this view is its screen. Typically, this view is a full-
screen view. More often than not, the view also has subviews. Thus, a view controller
controls a view hierarchy. Because the view is the root of this hierarchy, when the view
of a view controller is added as a subview of the window, the entire view hierarchy is ad-
ded.
Creating HypnoTime
Create a new iOS project from the Empty Application template. Name this project Hyp-
noTime and configure the project as shown in Figure 7.1 .
Figure 7.1 Creating a new project