Baboo offers a background slider to your wordpress website, its easy to install and easy to use.
Upload your own overlay styles to make your slider unique
Upload unlimited slides
show/hide Overlay
show/hide Title
show/hide Controls
show/hide Progression Bar
Please make sure the header, footer and navigation is not styled by a html or body tag, if it is the slider will work 100% as normal but because it sites above the html and body tag it will hide the background. Hence its a background slider 
I would like to thank:
Tested on the latest 3.4 version of wordpress