Currently have I implemented iAd and AdMob to each and every view controller in my Xcode project. I have about 6 view controllers and every time I switch back and forth between them one adbanner disappear and another appears. I want to make only one single adbanner for all view controllers. So even though its a transition between two view controllers, only one adbanner will be visible and it will not disappear and appear again.
But I also need to reach it from each class. So I can show it and hide it when I want to.
I would appreciate a ditailed step-by-step instruction.
INFO: I am using storyboard. I am developing for iOS 6.0 and higher. I am using navigation controller.