A mobile user apparatus including: user output circuitry including an integrated display for displaying content to a user; an interface configured to communicate with any of a plurality of accessory apparatus, in possession of different users; and processing circuitry configured to: execute multiple applications at the same time including a first application and a second application; provide output commands of the first application to the integrated display; and provide output commands of the second application to a mobile accessory apparatus in possession of the different user via the interface. A mobile accessory apparatus including an interface configured to communicate with a mobile user apparatus in possession of a different user that is configured to execute multiple applications at the same time including a first application at the mobile user apparatus and a second application, wherein the interface is configured to receive output commands of the second application via the interface; user output circuitry including an integrated display configured to respond to the received output commands of the second application; and user input circuitry configured to provide user input commands to the second application at the mobile user apparatus via the interface.