iOS Present modal view controller on startup without flash

Question

I\'d like to present modally, at first startup, a tutorial wizard to the user.

Is there a way to present a modal UIViewController on application startup

Answer 1

Bruce's upvoted answer in Swift 3:

if let vc = window?.rootViewController?.storyboard?.instantiateViewController(withIdentifier: "LOGIN")
    {
        let launch = UIStoryboard(name: "LaunchScreen", bundle: nil).instantiateInitialViewController()!
        launch.view.frame = vc.view.bounds
        launch.view.autoresizingMask = [UIViewAutoresizing.flexibleWidth, UIViewAutoresizing.flexibleHeight]
        window?.makeKeyAndVisible()
        window?.addSubview(launch.view)

        //Using DispatchQueue to prevent "Unbalanced calls to begin/end appearance transitions"
        DispatchQueue.global().async {
            // Bounce back to the main thread to update the UI
            DispatchQueue.main.async {
                self.window?.rootViewController?.present(vc, animated: false, completion: {

                    UIView.animate(withDuration: 0.5, animations: {
                        launch.view.alpha = 0
                    }, completion: { (_) in
                        launch.view.removeFromSuperview()
                    })
                })
            }
        }
    }