Please note, this blog entry is from a previous course. You might want to check out the current one.
Lecture #6 starts with a short demonstration on how to use abstract view controller classes and their sub classes.
The theory part of the lecture introduces how multiple MVCs work together to be specific navigation controllers and segues, which is shown in another demonstration.
The lecture closes with an explanation of tab-bar controllers.
The lecture as well as its slides are available via iTunes called “6. Views and Gestures”.