You can still put the UITabBarController in the App Delegate, when the login is done, just tell the app delegate, and switch the them.
If your Application is Navigation Based App, then Create TabBarController(with ViewControllers how many you want to add) and add it on Navigation Controller, like this.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.