Architecture that generates a companion window in combination with a source application experience to enable the accomplishment of a side task yet not switch away from the context of the source application. The companion window experience is a window that is rendered proximate (e.g., beside) a user's source application experience, in a predictable location, and with a predictable user model for invocation and dismissal. The companion window allows the user to retain full visual context of the associated source application experience, while rendering activities that directly pertain to the source application experience or activities that allow the user to interact with two applications.