Aside from your daily workhorse apps, what are some apps that you use that allow you to have fun and explore our world?

For my Android I love to use the Sky Map at night to help me identify stars and constellations. I have recently added Aurora that maps the Northern Lights events and alerts me to times and days for high probability of seeing the Northern Lights. What are some other really cool useful apps you have on your phones?

Topics: health, fun, diet, cell phones, fitness, apps, navigation, exploration