What on Earth app for iPhone and iPad

Have you ever wondered how many countries you have been to? Or how many states in the US you have visited?
What on Earth lets you track when you have visited these places and give you a percentage completion of a particular category (such as Wonders of the World, or capital cities). Once checked in to a location then you can add dates and images to remember your trip.
Wondered how you compared to your friends and family? Here you can look at whether your friends have been to a location, or are closer to completing the category than you.
We are adding new categories all the time, so please tell us What on Earth you would like to track.