You can add some folders and images and Wally will set a different wallpaper each certain time. Choose a local folder or an Interent service like Panoramio or Flickr. Wally will use those pictures to set them as wallpaper. It's easy.
You can configure the intervals of time and the folders where the pictures are located, frames, style of wallpaper and more.
If you have a lot of wallpapers and you don't know which one you want to set today, let Wally do its job.