This plugin hasnt been tested with the latest 3 major releases of WordPress. It may no longer be maintained or supported and may have compatibility issues when used with more recent versions of WordPress.
This plugin deserves a prize for being simple and effective. Only 2 fields to fill out, plus your own "under construction" page.
I installed and then un-installed 4 other plugins, each of them doing an ok job and providing lots of unnecessary features. Most of these plugins limit what you can display and where any text is displayed.
Simple and fast - what more do you want?