Described herein are various technologies pertaining to a graphical user interface (GUI) for a hub application that is displayed concurrently on a display with a graphical user interface (GUI) for a client electronic health record application (EHR). The hub application includes a ribbon that comprises several selectable buttons that respectively represent supplement applications, wherein a supplement application is configured to generate events based upon a current context of the client EHR. The GUI of the hub application is updated when a supplement application reports an update to the hub application, wherein the update to the GUI can include rendering a badge on a button that represents the supplement application.