Let's go ahead and take our stretchy header effect and kick it up a notch by introducing a visual blur as we drag up and down. This is done very simply by adding a UIViewPropertyAnimator in our HeaderView class. In addition to this animator, we'll modify the fractionComplete property that allows us to control the amount of blur that is applied. Enjoy.

### iOS 13 Update for Blur **HeaderView.swift** ```swift fileprivate func setupVisualEffectBlur() { addSubview(visualEffectView) visualEffectView.fillSuperview() // iOS 13 UPDATE: You now have to set .effect to nil, otherwise blur instantly begins at full intensity animator = UIViewPropertyAnimator(duration: 1.0, curve: .linear, animations: { self.visualEffectView.effect = nil }) // Reverse animator so that we can use fractionComplete of 0 as our "starting point". You don't have to do this, but it makes for easier calculations in your StretchyHeaderController.scrollViewDidScroll animator.isReversed = true animator.fractionComplete = 0 } ``` Download the project to see the full changes.