Quick Challenge: OH HALP, HOW I PULL REQUEST!?

I went with a custom sub-class of CALayer with a custom property called "animationProgress". I created a CASimpleAnimation to animate the property from 0.0 - 1.0. The setter for that property reported its value to the instance's delegate. I then used the reported value to compute where in the number sequence that value fell. The rest of the time was simply spent polishing the optional interface elements.