Outdoor photographers are going to love PhotoPills. This US$9.99 app is a treasure trove of information for photographers who do most of their work outside.
The app allows you to plan your photography for any location on earth by letting you know where the sun and moon will be, provides depth of field calculations for any of hundreds of DSLR cameras, can help you determine the number of exposures needed for time lapse videos, and even calculate how much space images will consume in your camera storage.
I especially like the augmented reality views of the Sun, Moon, Milky Way and the North Star (Polaris) so you can know exactly where to position yourself for that dramatic photo of a striking sunset or sunrise.
PhotoPills can also perform calculations for determining the best long exposure times or determine the field of view for any camera/lens combination. It even tells you when the moon is closest to us or at its greatest distance, and of course you will get a graphical indication of the moon phase.