Unsplash Wallpaper is a free wallpaper app that I really like. It uses the work of collaborating photographers on Tumblr as its wallpaper database, so it’s very rich in terms of quantity, and most of them are nature and lifestyle images, which is very much to my taste.
You can use hotkeys to switch to a new wallpaper, choose “Randomize” to display random wallpapers, blacklist any you don’t like, or customise the interval between wallpaper changes, such as every hour, every 12 hours and so on.
If you use HiddenMe to hide your desktop icons, your desktop will not automatically update when you change your wallpaper, so you will need to turn off HiddenMe to do so.