Apermo AdminBar
by Christoph Daum on WordPress.org
This plugin allows you to add links between a development, staging and live version of your website, and adds them to the AdminBar.

The basic idea of the plugin, 3 instances of a website, with 3 distinct color schemes and quicklinks between the instances.
This plugin enhances the AdminBar and adds links to development, staging and live version of your website, furthermore it allows you to choose a color scheme of your AdminBar for all users on a website, including the frontend.
You also have to option to control the robots.txt visibility settings, in the newest version you get a watermark for posts that are in draft or scheduled, and a keyboard shortcut to hide the adminbar.
If you want to participate in the development head over to GitHub!