WP Sticky Header is the plugin to display some content/notification bar on top or bottom of the pages. It can be closed and the colour of the background and text colour can be modified. Notification bar can be shown on all pages or only in home page or in all posts or in selected pages / posts. Once installed and activated, settings menu will appear on the dashboard. One can customize the notifications bar. Auto close option is also available.
This plugin is available for download to be used on your WordPress self-hosted installation.