What it does
This plugin on it's own does absolutely nothing but waste CPU cycles. You can however use this plugin together with another plugin that supports it (or within it's own plugin) to create some pretty slick stuff.
How to use it in your own plugin
Simply listen for a MessageBarSetEvent in your plugin, and add the depend line in plugin.yml.
Use MessageBarSetEvent.setMessage(String), to set the message for your players.
You could end up with something slick looking like this :o