This quiz application from the Sierra Club shows you the differences between closely linked animals (dolphins vs. porpoises), weather (hurricanes vs. typhoons) etc. Being able to distinguish a manatee from a dugong could tell you which continent you're on (if you're in doubt). Knowing the difference between a porcupine and a hedgehog lowers your risk of grievous bodily puncture. Deducing that the wiggly thing underfoot is a king snake and not a coral snake could save your life. This application offers entertaining illumination on the characteristics that set one animal (or plant or geological feature or meteorological event) apart from its seemingly similar neighbor. A portion of this mobile application's sales proceeds are donated to the Sierra Club for environmental protection causes.