Image Picker Controller

@IBAction func experiment() {

    let controller = UIImagePickerController()

    self.presentViewController(controller, animated: true, completion: nil)

}

Activity View Controller

@IBAction func experiment() {

    let image = UIImage()

    let controller = UIActivityViewController(activityItems: [image], applicationActivities: nil)

    self.presentViewController(controller, animated: true, completion: nil)

}

Alert View Controller

@IBAction func experiment() {

    let controller = UIAlertController()

    controller.title = "Test alert"

    controller.message = "This is a test"

    // Dismiss the view controller after the user taps “ok”

    let okAction = UIAlertAction (title:"ok", style: UIAlertActionStyle.Default) {

        action in self.dismissViewControllerAnimated(true, completion: nil)

    }

    controller.addAction(okAction)

    self.presentViewController(controller, animated: true, completion:nil)

}