3D National Parks is a collection of photos from 28 US National Parks. Each photo can be viewed in 2D or 3D (with the aid of red-cyan 3D glasses) and comes with a brief description of the park and the specific scene being displayed. Although the focus is on natural rock formations, plants, animals, and man-made objects do intrude where suitable.
It's a hard sell to make a commercial app that's essentially a picture slideshow, even if those pictures can be seen in one form of 3D. To add value, some context is given for each image, although you may want to take any factoids these captions supply with a grain of salt. For example, a picture of a raven is accompanied by the "fact" that the primary difference between ravens and crows is that ravens have an additional tail feather - but in actual fact, size is a much more significant separator, and I was unable to find corroboration on the feather count distinction.
Questionable captions aside, you can find photos from these national parks and more all over the Internet for free. But if you don't mind spending a few bucks to scout out some natural scenery and if, even better, you have some unused red-cyan glasses lying around, give it a shot.
Sam's Protip: To my mind, viewing 3D with side-by-side views is preferable. This technique, in which the viewer essentially crosses their eyes to combine the two constituent views, preserves the color of the original image, unlike anaglyph imaging. It can be tricky to learn, but the results upon success can be astounding.
