View controllers become more interesting when the user’s actions can cause another view controller to be presented. In this book, you will learn a number of ways to present view controllers. You will start with a UITabBarController that will allow the user to swap between instances of BNRHypnosisViewController and BNRReminderViewController.
UITabBarController keeps an array of view controllers. It also maintains a tab bar at the bottom of the screen with a tab for each view controller in this array. Tapping on a tab results in the presentation of the view of the view controller associated with that tab.
In BNRAppDelegate.m, create an instance of UITabBarController, give it both view controllers, and install it ...