The app has all different categories for you to browse through and easily find images related to your interests. Tap each one and slide your finger through all the options to find the picture you like best. If you're not sure about any photo, you can enlarge it to see exactly how it would look on your screen. As soon as you find the one for you, all you have to do is tap to set it as your background.
The great thing about Backgrounds (HD Wallpapers) is that it offers a new image daily to change your wallpaper automatically, so you can have a fresh-looking screen every day with no effort at all.