Here is a free Joomla! 2.5+ compatible icon manager for the administrator console. I wrote it to take full advantage of the 2.5 MVC, so it allows for an infinite amount of icons that can be placed in categories and have ACL rules applied to them.
The package contains both a component and a module. Use the component to add/delete/publish, etc new icons (provide a link and an image). A sample icons is included to show you what values are needed.
The module must be published in the 'icon' position for the administrator. You can copy the module to make additional icon groupings. The module can also be configured to display icons from all categories or from specific categories.
The project is hosted on GitHub, so fork it and send me a pull request or let me know about desired features!