Hi,
About the app.
It is the complete sample which you provided earlier. One change i did: The banner will show at the bottom.
For a better overview I also excluded the UI for Interstitials etc and added the (missing) functionality for Hide() and Show(). Please also note the red number showing the amount of touches registered by the app (Unity -> Input.touchCount);
To reproduce:
After starting the app touch the screen at the bottom. Note how the number switches to one.
Click Request Banner.
After it shows click Hide Banner
Tap the screen where the banner has been before. Note how the Number stays at zero.
Click Destroy Banner
Tap the screen where the banner has been and note how the number becomes one.
Special Case:
Request Banner in Portrait mode, turn Phone to Landscape: Note how touches beside the banner are not registered.