System Preferences

An application was installed on Petronella Osgood's computer by 10 May 2020. Its logo was a metallic square with a circular hole in its centre, including a gear in front of a darker metallic backdrop and a red circle in its top-right corner including the number "1". (WC: The Zygon Isolation)

Behind the scenes
While the application was not named in WC: The Zygon Isolation, the application was named "System Preferences" in the real world, and was an application which allowed users to modify various system settings. Although not stated in WC: The Zygon Isolation, the red circle was present because she had 1 notification.