Mac users seem to be divided into two camps. The first group uses the Desktop more or less like a real desktop; a place to drop files and folders; something of a workspace. The second group avoids the Desktop metaphor and treats it as it really is– a folder that holds frequent and recently used files and folders.
The difference between the two usages is obvious. With latter, the Desktop background wallpaper is seldom see, while with the former, the Desktop background wallpaper is cluttered with files and folders.
SlideTop is a free Mac app aimed at the Desktop user who wants to view background wallpaper photos from collections as a photo slideshow.
There’s not much going on with SlideTop, hence the free price tag. Create a folder of photos and SlideTop adds them to the Desktop as individual slideshows.
Create a folder of photos for each corner of your Mac’s screen (even works with multiple displays connected to your Mac).
SlideTop cycles through the photos, presenting them as a slideshow on your Desktop.
Not bad for free, right?
My personal preference would be to have a stack of photos from a folder of photos float on top of both Desktop and open app windows and cycle through the photos. I treat my Desktop as a folder, so anything plunked on top of the wallpaper is usually obscured by app windows.