AppDelegate for Storyboard less

AppDelegate.swift

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
        // Override point for customization after application launch.
        let window = UIWindow(frame: UIScreen.mainScreen().bounds)
            window.backgroundColor = UIColor.whiteColor()
            window.makeKeyAndVisible()
        self.window = window
        
        let vc = UIViewController()
        let nc = UINavigationController(rootViewController:vc)
        window.rootViewController = nc
    
        return true
}