Work on your website behinds the scenes while you display a Maintenance Mode page to your visitors.
I don't like just giving a 1* review but since it just didn't work, and someone else who experienced this received no support on the help forum, there's not a lot more I can do!
Preview looked fine... just didn't actually do anything when enabled. Yes I tried multiple browsers, cleared cache/history etc etc..
Was running wp3.9
It used to be a great plugin...now it has been stripped down so much, and stuffed full of ads, that it is no longer worth using over the alternatives. Would not recommend this plugin as it is now.