thisisbd/silverstripe-maintenance-mode (packagist): SilverStripe Maintenance Mode Module.  Allows an administrator to put site in offline mode with 503 status to display a 'Coming Soon', 'Under Construction' or 'Down for Maintenance' Page to regular visitors, whilst allowing a logged in admin user to browse and make changes to the site.
Keywords: silverstripe|under construction|Maintenance mode|coming soon|utility page|offline page|landing page