Star Walk was one of the first apps to create a form of digital stargazing with augmented reality. Launch the app, hold it over your head at the night sky and it creates a virtual window into the heavens.
The Star Walk database has over 200,000 celestial bodies and a substantial bank of information about planets, satellites, and constellations. One of the coolest features is the Time Machine, which will explore the map of the night sky from years past or into the future.
Star Walk ($2.93)