I was playing around with XCode and came up with this simple counter:

You hit the count button and it counts. That is all.
If you’re crazy enough to want to try it, here it is: Counter 1.0.dmg
It’s built on Mountain Lion, so I very much doubt it’ll work on anything else.
Why did I do this? Because I wanted to play with some Cocoa objective C and lacked any other ideas.