Sky Spy is your window onto the night sky.

What's that bright thing in the sky? Point your iPad or iPhone at it, tap the screen, and Sky Spy will tell you! Would you like to know where Mars is right now? Ask Sky Spy, and arrows will appear to guide you to Mars.

You can find or identify all of the visible stars, planets, our Sun and our Moon. You can also find the constellations or find the position of objects in right ascension and declination so you can point your telescope to just the right spot.

Sky Spy uses the position of your iPad or iPhone, including the compass built into iPad and iPhone 3GS and later models, to tell what you are looking at. You’re not left out if you have an older iPhone or iPod Touch, though. Sky Spy will let you manually dial in the compass heading, and will still use the tilt of the iPhone to tell how high you are looking in the sky.

Sky Spy is the ultimate planetarium program, because it helps you look at the real thing—the night sky above you—and labels what you see with clear informative text, common names for stars, borders for the constellations, and guides to help you understand what you are seeing. It's a great example of augmented reality.

Sure, you can use a planetarium anywhere—even Sky Spy works that way—but the very best planetarium is the real night sky with labels from your iPad or iPhone!