I have a simple NavigationController based app. The main window shows a TableView and selecting an item loads a sub-view. I used Interface Builder for UI views.
Now
I do this in a couple of my apps. The trick to adding a tab bar to a navigationController based app is to NOT use a TabBarController. Add a Tab Bar to the view, make the view controller for that view a TabBarDelegate, and respond to user selections on the tab bar in the code of the view controller.
I use Tab Bars to add additional views to the Tab Bar's view as sub-views, to reload a table view with different datasets, to reload a UIPickerView, etc.