Ranwall is an Open Source wallpaper app providing random images pulled from pre-selected websites that can easily be set as wallpaper.
It includes several websites that it pulls images from for use as wallpaper. You can check out the providers from the settings option on the interface. The images that we tested were nice, crisp, and tasteful. You have the option to save as or set as wallpaper, giving you the power to get it now or save the image for use later on.
Ranwall also has a few settings options to play with, like resolution, wallpaper resizing, previews, etc. It is a simple way to get new images for use as wallpaper minus the searching around.