We recently needed to add a tutorial to a board game (see SLTutorialController), and realised that we needed a way to highlight various controls and other user interface elements that the user should interact with next. A common way that this is handled is by making things glow, often with an animation. So, we wrote UIView+Glow. It's a very simple category that adds two methods: startGlowing and stopGlowing. When you call startGlowing, the view will start to pulse with a soft light; this effect is removed when stopGlowing is called.
You can see a video of it in action here:
It's available on our GitHub now!