You can put your site to under maintenance mode when you are developing your site and don’t want people to see the unfinished site. It’s also helpful if you need to put it under maintenance for a while when something is broken or needs an upgrade.
You can activate this module from Flexia > Modules from your WordPress Dashboard :
Customizing Under Maintenance Page
After activating the module, click on “Customize” link and you will see the configuration options :
You can set the title, tagline, description, background image and set the launching date to get beautiful cowntdown.