Extracted 11JAN2012 from http://www.businessinsider.com/best-augmented-reality-apps-for-iphone-and-ios...
Ever since Apple added gyroscopes to the iPhone and iPad, augmented reality apps have no longer been the sluggish and cumbersome oafs they used to be.
Gyroscopes tell your iPhone which way you're facing, and which way is up or down. Couple that with GPS and a built in compass, and suddenly your device has a good feel for where you are and which way you're looking.
Using these tools, apps can create a virtual world right on top of the real one.
- Augmented Car Finder
- Metro AR
- Star Walk (my personal favorite, see picture below)