SkyView - Explore the Universe ($0.99) by Terminal Eleven LLC is a stargazing app that implements augmented reality to "explore the universe."
Have you ever wondered where the constellations are? How about the planets? Or where the sun and the moon will be at certain times of the day? Since I live in the city, it's hard for me to see all the cool stars at night, but SkyView can help me see what nature has to offer.
SkyView implements layers of augmented reality on top of your iPhone's live camera view so you get a 3D interactive guide to everything that happens in the sky.
On the initial launch, you'll open up to your camera and the layer of AR. The AR view may or may not be calibrated, but you can adjust the calibration manually in the Settings. Since it's manual, you may need to know a bit about directions from where you are; swiping the screen left or right will adjust the augmented reality layer.
Additionally, you can adjust other settings of the AR layers as well. You can toggle the visibility of Sun, Moon, Planets, Dwarf Planets, Satellites, Stars, and Constellations; you have complete control over what you want to see in SkyView.
The size of planets and satellites can be tweaked to your liking, along with the custom date and time, in case you want to see how the sky will be next week. Another location besides your current one can be entered if you're the curious type or planning ahead.
SkyView provides a tutorial section that can be viewed at any time (but it is also shown during the first launch) in case you forgot how to use the app.
The augmented reality view is quite amazing. You'll see the stuff that you have toggled to see, and a tap will select an item on the screen. When selected, the bottom will display the name of the item and bring up more information about it. There's usually a good breadth of information, so you can tap the arrows to dig deeper.
In addition to displaying information, if something like a planet or the sun and moon are selected, there will be a "Sky Path" to follow. This path shows where the object will be in the sky during a 24-hour period. Pretty nifty, right? You can even search for an object, and then there will be an arrow on the screen to direct you to where it is.
SkyView also features information and tracking about the final NASA space shuttle missions, compass and horizon display, and uses the gyroscope on the iPhone 4 and iPod Touch 4th generation. The interface is also very slick and well thought out.
If you've ever been looking for a stargazing app for your iPhone, then this definitely the one to get. Explore the universe for only $0.99 for a limited time! Afraid of committment with that spent dollar? There is also a free version to try out.