I made this cool little game when I visited Questacon (a science museum in Canberra) and became intrigued by how the brain is good at estimating but bad at being accurate. These games are designed to test your ability to measure time. It has gamecentre leaderboards to see how you compare to the general population.

Here are a couple of screenies

Download at https://itunes.apple.com/us/app/time-to-measure/id820864672?mt=8