Star Rover HD, from developer EEFan, Inc., is a real-time planetarium app for the iPad. The objects on the screen, including the moon, planets and other heavenly bodies, are in exactly the same place as they are in the night sky outside, using the user's location data to make this happen.
The planetarium app boasts over 120,000 stars from the Hipparcos Catalogue, a high-precision star catalogue published in 1997 that was based on the European Space Agency's satellite in operation during the late 1980s and early 1990s. The other features of this app include all 88 constellations, planets and their moons, our own moon phases, real images of nebulae from the Messier catalogue of 1771, and realistic Milky Way, atmosphere and sunset data.
If that's not enough for the star loving iPad owner, an online User Guide is available. Any fan of the heavens can see the utility of such an app, viewing the night sky with far greater resolution and an overlay of real-time information and data -- far better than squinting through a blurry telescope and consulting a paper book, yeah?