I was developing a website intended to be viewable only by logged-in users, so I looked specifically for a site-wide splash with an admin login form that would redirect to the frontpage after a successful login. This plugin delivered that key functionality.
Aside from being able to include the site name and description on the splash page, there is not much in the way of customization features. But the source code is very simple and clear, so if you are comfortable with hacking, you can customize the graphic design by editing the plugin source code. Otherwise you are stuck with the developers' graphic design that isn't very sexy.
Please note that it appears the plugin is no longer maintained by the developer. So it may not work on all platforms of WP. But it worked for 3.6.1. FYI the theme I was using is Elegant Themes' "Foxy" but it probably has no bearing on the operation of this plugin.