   public var duration: NSTimeInterval
   public var isPlaying = false
 
-  init(view: UIView, destination: TutorialViewPosition, duration: NSTimeInterval = 1.0) {
+  init(view: UIView, destination: TutorialViewPosition, duration: NSTimeInterval = 0.5) {
     self.view = view
     self.view.setTranslatesAutoresizingMaskIntoConstraints(true)
     self.destination = destination

    super.init()
  }

  func animate(alpha: CGFloat) {
    if !isPlaying {
      isPlaying = true

      UIView.animateWithDuration(duration,
        animations: {
          [unowned self] () -> Void in
          self.view.alpha = alpha
        }, completion: {
          [unowned self] (done: Bool) -> Void in
          self.isPlaying = false
        })
    }
  }


  public func show() {
    view.placeAtPosition(destination)
    view.hidden = true
  }

  public func play() {
    view.hidden = true
    animate()
  }

  public func playBack() {
    view.hidden = false
    animate()
  }

  public func move(offsetRatio: CGFloat) {
