Simple plugin provides easy setuping coming soon page by clicking on dropdown menu.It offers you two site states:Usual running site and Coming soon page.Independent of selected state, logged administrators always see the full, running site. This is very useful for site maintance and fixing.you can create a custom theme by creating coming-soon.php file into your active theme folder.
To add Simple Coming soon And Under construction wordpress plugin to your WordPress blog
1. Download Simple Coming soon And Under construction wordpress plugin from this link.
2. Unzip and upload it to your WordPress wp-content/plugins directory.
3. Login to wp-admin. In your admin dashboard click plugins and activate the Simple Coming soon And Under construction wordpress plugin.
4. Then go to Settings menu and click Simple Coming Soon.
5. change the site state to Coming soon page and adjust Theme Options and click Save changes options.
6. Now log out your wordpress admin and check your site.