Maintenance mode is for preventing any users other than administrators from using the site while maintenance is taking place, though it's not designed to prevent user access during version upgrades. When users attempt to access a course when your site is in maintenance mode, they obtain a message informing them that the site is in maintenance mode. If you wish, you can create a customized maintenance mode message, perhaps stating when the site will be available again or giving the reason for doing maintenance.
Demo
http://demo.alfnyhost.com/index.php?a=maintenance-mode
Product Page
http://www.alfnyhost.com/products.php?action=p&pid=4
Features
Language
English - German
Template system
The Maintenance Mode ++ have it's own template system you can customize the default template or create a new one
Responsive Ready
The Maintenance Mode ++ template features a fully responsive framework that looks fantastic on any mobile device
Bootstrap 3.1 HTML5 & CSS3
The Maintenance Mode ++ template is an awesome template design with HTML5 CSS3 and Bootstrap 3.1
Font Awesome Icons
Font Awesome gives you scalable vector icons that can instantly be customized size, color, drop shadow, and anything that can be done with the power of CSS.
Background
5 Full Screen Background Types : Youtube video, Ken Burns Image Slideshow, Fade Image Slideshow, Continuous Fade and Solid Color background.
Count down
2 Styles of count down timer, 3D Square and 3D Rounded (Piechart)
Patterns
41 Overlay Pixel Patterns for the Fullscreen Background with customizable transparency.