The basic premise of CoverOver is to hide underlying content with an overlay. Such uses could include displaying important messages, overlaying a slideshow or video with introductory text, or pre-warning site visitors about sensitive or upsetting content that might exist. CoverOver can either cover over individual stacks. Alternatively you can use the configuration menu (in the settings) to cover the entire page with an overlay. Options also exist to reverse the overlay effect, apply a background fill, and adjust the z-index layering. A simple system of CSS and vanilla Javascript is used to create the overlay effect; therefore avoiding bulky libraries or bloated code to slow down your pages. Just the bare minimum required, to get the job done.