PrivacyScreen

Privacy Screen is a Chrome Extension that hides HTML Body while mouse not hovering over window.

Under the configuration, you will be able to choose the mode in which the extension operates (blacklist/whitelist)
With blacklist mode, site you enter to the blacklist will be hidden when your mouse is not over the window. In whitelist mode is the opposite of blacklist, and will apply the privacy screen to all sites, except the ones entered into the whitelist.