FPPopover provides an alternative to the native iOS UIPopoverController, adding support for iPhone and additional opportunities to customize the look and feel of the popovers.
When the GADBannerView added, the top window's the most top view is GADAdView, which contains GADBannerView. When GADBannerView is at the bottom of screen, FPPopover get the CGPoint of origin is negative number, so there is FPPopover view will displayed.
When the GADBannerView added, the top window's the most top view is GADAdView, which contains GADBannerView. When GADBannerView is at the bottom of screen, FPPopover get the CGPoint of origin is negative number, so there is FPPopover view will displayed.