Maintenance PRO v3.5.1 is packed with advanced features, for a powerful and effective maintenance mode splash page that stands out from the crowd. Maintenance PRO builds on everything you loved about the free Maintenance WordPress plugin (available on wordpress.org), and takes your “Coming Soon” or “Under Construction” page to a whole new level.Both versions tested to WordPress 4.8.
Demo
https://codecanyon.net/item/maintenance-pro-wordpress-plugin/2781350