From looking at the MyTabBar app from Lecture 7 you can see that ViewControllers can be created with IB or programatically, like many other things in Xcode/IB. The important thing is that in IB its not flexible; the way i see it if you create it in IB youre pretty much stuck with the design but in Xcode you can add things based on variables you get from the user or a data source. EXAMPLE:
1. I went thru a tutorial from LittleComputers.net where we created a tabBarController with 2 tabs and later on added a NavigationController to one of the tabs. Basically i dragged a tabcontroller from the IB Library (default of 2 tabs) and a navController. I then had to create the view controller class files manually with their xibs and connect the xibs to the respective class files. But thats it, once theyre setup, i couldnt add more xib files.
2. With lecture 7, looking at the MyTabBar app i can see how easily to create a view programatically and that gives you the flexibility to create more views based on user response or dynamic data sources.