SplashGate is a splash page plugin. It does optional full page redirection that won’t mess up search engine indices, and makes permanently available a url that will always redirect to the actively splashed page. Alternatively, splash page content can be made to appear as an overlay (using fancybox) instead of redirecting.
Splash management is centralized, so it’s easy to see if a splash page is active, which page is the active splash, and to easily disable or enable new pages. There is also a dashboard widget, recurrence timing options, and overlay sizing configuration.