Sometimes you may be migrating your blog to different server or importing blog posts or database from backup. Or it may even happen that your blog is broken due to some configuration problem in your hosting server. Then it is somewhat professional to show a maintenance page to your visitors. It gives a good impression to the readers and gives them some sort of info about when to come back.
That’s where I have found this WordPress plugin real handy. Without any hardship you can show a real pro-looking maintenance page to the users. And moreover you can give access to the real state of the blog depending on the WordPress user role. Like your blog administrators can have access to both front-end and back-end while subscribers can only have access to the back-end i.e. WordPress dashboard and they will see maintenance mode in front-end.
And you can write your own custom message and use dynamic placeholders to show your blog url, title and expected time when your blog will be live again. But one thing that you have to remember is that maintenance mode will not get deactivated automatically. But that is not that serious issue as you can show different message instead of expected time in that case. You have option to show messages like “coming back soon” when the time that you entered expires automatically.
Another nice little thing that I found worth mentioning. You can select urls that you want to exclude from maintenance mode. Suppose you want to keep your About And Contact pages working. Then you just have to specify the url paths in the plugin’s options page. And you can keep your trackback and feeds active on the same page.
Lots of options, easy interface 
If you experiment with your WordPress blog a lot, then it is good to have it.
