This plugin provides easily create a maintenance mode page for your WordPress site.
Ability to enter maintenance lockdown mode: force-logout all non-administrators, prevent logins from non-administrators, and disable commenting.
WIP Incoming Lite allows you to manage a coming soon page for your WordPress site.
Display a maintenance mode page automatically while you are away from your development or staging site.
A handy toolkit can easily tweak up and speed up your wordpress, including pack the resources, unload the * unnecessary, maintenance mode, etc.
Allow you to send email each time a plugin or WordPress core is updated.
A plugin that redirects you to a post with no tags (or failing that, a random post) so that you can add tags to those old posts of yours.
This plugin monitors installed WordPress plugins on your installation for updates and notifies via email when they are available.
Uses WP "pseudo-cron" system to automatically purge OpenX statistics data.
OSM Maintenance will allow you to put your WordPress site in Maintenance Mode.
RS Coming Soon plugin Creates a page for your Website while it's under construction and collects emails from your visitors and show in dashboard.
A plugin with common features missed in WordPress, like favicon, meta tags, adding HTML to head and footer, WordPress e-mail from header filter, etc.
adds a splash screen to your site for construction or maintenance reasons. Has a configurable countdown.