Solar Walk

Solar Walk is an astronomy app that takes you on a virtual tour through the beautiful Milky Way (not just through the solar system as its name might suggest).

The free version of the app is focused on Saturn (you can get more by paying within the app), but you can still move through space with some freedom. Of course, you can take a look at Saturn's moons, and also check out some facts about the planet itself, such as its distance from the sun or its mass.

Though focused on Saturn, Solar Walk lets you get considerably far away from that planet to take a look at the Oort Cloud and other stars within the Milky Way, and of course get an external view of the galaxy. At this level, the information available is less than within the Solar System, but it's still interesting.

Solar Walk is an educational astronomy app that is both beautiful and interesting and lets you travel through time and space from your Android phone.