Amazon’s FREE Android App of the Day is Counting with the Very Hungry Caterpillar. The most-loved Caterpillar in the world is hungry…Very Hungry! Find and eat all of the Caterpillar’s favorite foods while you learn the fundamentals of numbers and counting, in this beautiful, interactive math game for kids aged two years and up. (Even adults will like playing level five!) Offer is available today only (3/20).