PresentAlertAboveAnyView.swift

// so it won't compile on a lower version.
extension UIAlertController {
    
    func show() {
        present(animated: true, completion: nil)
    }
    
    func present(animated animated: Bool, completion: (() -> Void)?) {
        if let rootVC = UIApplication.sharedApplication().keyWindow?.rootViewController {
            presentFromController(rootVC, animated: animated, completion: completion)
        }
    }
    
    private func presentFromController(controller: UIViewController, animated: Bool, completion: (() -> Void)?) {
        if  let navVC = controller as? UINavigationController,
            let visibleVC = navVC.visibleViewController {
            presentFromController(visibleVC, animated: animated, completion: completion)
        } else {
            if  let tabVC = controller as? UITabBarController,
                let selectedVC = tabVC.selectedViewController {
                presentFromController(selectedVC, animated: animated, completion: completion)
            } else { if let presentedViewController = controller.presentedViewController { presentedViewController.presentViewController(self, animated: animated, completion: completion)
            } else {
                
                controller.presentViewController(self, animated: animated, completion: completion)
                }
            }
        }
    }
}

 //Present alert on always on top of any other view . Alternate approach
            
let alertWindow = UIWindow(frame: UIScreen.mainScreen().bounds)
alertWindow.rootViewController = UIViewController()
alertWindow.windowLevel = UIWindowLevelAlert + 1;
alertWindow.makeKeyAndVisible()
alertWindow.rootViewController?.presentViewController(alert, animated: true, completion: nil)


//source http://stackoverflow.com/questions/26554894/how-to-present-uialertcontroller-when-not-in-a-view-controller/36540728#36540728