Have you ever missed a Joomla! update for example a security update that set your site and users to an avoidable risk? With this plugin you will be notified as soon as there is an update available. And now when you click on the icon AND have the Update Manager for Joomla! installed,
it will take you to the components interface to take you through the steps of updating your site.
How it works
You simply install the plugin with the default Joomla! Extension manager and publish it in the Plugin manager. That's all you have to do. As soon as there will be a newer version available you will see this icon in the top bar: 
(beside the preview link) that informs you about the new version and if you click it you will be directed to joomlacode.org where you can download the necessary updates.
Changelog
v1.2:
- checks to see if the Update Manager is installed, if that is the case, clicking on the icon will take you to the component's interface.
v1.1:
- fixed error message on uninstall that the xml-file could not be deleted (even if it was deleted).
- fixed error on detecting version x.x.9 as lower than x.x.10