It was a really fun project – combining stats data together with an interested UI design. I implemented everything using ReactiveCocoa, natch. Nothing about the implementation beyond that is that technically interesting. What is interesting is that my involvement in the project didn't end with implementation.
I shot the original concept video (which we later reshot with the talented visual designers at T+L) and I also contributed video editing (new for me), audio editing, and photography. I can't imagine working anywhere else and getting to flex my creative muscles in quite the same way.