Russ Shanahan's submission

My solution is a bit hacky, but it's the only way I knew how to get the Apple EaseIn / EaseOut behavior for my tweened values.

I ended up adding a (mostly) invisible layer to the text layer, using Core Animation to tween the values, and then use a delegate callback from that invisible layer to update the UILabel with the new value.

I've done something similar in the past, except actually drawing the strings in the CALayer using CoreGraphics. Since I'd much rather leverage NSLabel's drawing, I used this approach in my wise old age. :-)