Sometimes, due to some technical issues, server related problem, or if you want to change some feature or theme of your live website, you require putting your site under maintenance mode. At that moment, Easy Site Maintenance extension is a boon for online merchants.  Easy Site Maintenance Extension allows you to put your online store in maintenance mode for specified period of time from the frontend and configure it from the backend.  http://store.biztechconsultancy.com/magento-easy-site-maintenance-extension.htm