Mac: Not a fan of keeping your wallpaper the same all the time? FreshBackMac is a simple little Mac app that will cycle through different wallpapers from a very of different sources. All you need to do is launch FreshBackMac, click the menu bar icon, then select the source you want. The app then pulls high resolution images from the likes of Nasa, 500px, Pixabay and even popular movies. You can set the refresh rate so your desktop's always fresh and new looking. It's a pretty simple way to keep your wallpaper fresh without doing any work.