Guake indicator lets you send custom commands through the D-Bus System. Commands can be manually edited in a XML file under ~/.guake.indicator or generated through guake-indicator edit-menu system GUI.
Guake-indicator sticks to your "System Tray" and displays your favorites commands retrieved from ~/.guake.indicator/guake-indicator.xml. If guake-indicator.xml does not exist, guake-indicator will create a default configuration file with some examples.