A mobile computing device for providing a content portal to an external display, the mobile computing device comprising: an integrated display; at least one processor; and one or more computer-readable storage media including instructions stored thereon that, responsive to execution by the at least one processor, cause the mobile computing device to perform operations including: displaying a content portal interface at the integrated display of the mobile computing device; receiving an input at the integrated display indicating a drag and drop gesture originating at selectable content (204a, 204b, 204c) and terminating at the content portal interface; causing display content representing the selectable content to be displayed at the external display device; and characterized in that: the display content includes a graphical user interface for an application; the integrated display includes an input interface representing functionality for using the integrated display for modifying the external display in a corresponding manner via input received at the integrated display; and the operations further include: receiving at the input interface of the integrated display a further input to control the display content at the external display device; and modifying the display content at the external display device based on the further input received at the input interface of the integrated display, the modifying comprising moving or resizing the graphical user interface. an integrated display; at least one processor; and one or more computer-readable storage media including instructions stored thereon that, responsive to execution by the at least one processor, cause the mobile computing device to perform operations including: displaying a content portal interface at the integrated display of the mobile computing device; receiving an input at the integrated display indicating a drag and drop gesture originating at selectable content (204a, 204b, 204c) and terminating at the content portal interface; causing display content representing the selectable content to be displayed at the external display device; and displaying a content portal interface at the integrated display of the mobile computing device; receiving an input at the integrated display indicating a drag and drop gesture originating at selectable content (204a, 204b, 204c) and terminating at the content portal interface; causing display content representing the selectable content to be displayed at the external display device; and characterized in that: the display content includes a graphical user interface for an application; the integrated display includes an input interface representing functionality for using the integrated display for modifying the external display in a corresponding manner via input received at the integrated display; and the operations further include: receiving at the input interface of the integrated display a further input to control the display content at the external display device; and modifying the display content at the external display device based on the further input received at the input interface of the integrated display, the modifying comprising moving or resizing the graphical user interface. the display content includes a graphical user interface for an application; the integrated display includes an input interface representing functionality for using the integrated display for modifying the external display in a corresponding manner via input received at the integrated display; and the operations further include: receiving at the input interface of the integrated display a further input to control the display content at the external display device; and modifying the display content at the external display device based on the further input received at the input interface of the integrated display, the modifying comprising moving or resizing the graphical user interface. receiving at the input interface of the integrated display a further input to control the display content at the external display device; and modifying the display content at the external display device based on the further input received at the input interface of the integrated display, the modifying comprising moving or resizing the graphical user interface.