In a system in which an in-vehicle apparatus and a smartphone are connected to each other, screen display switching cannot be performed with priorities of all the applications taken into account as respective terminals carry applications. A management block is provided in an in-vehicle apparatus or in a smartphone. The management block holds priority definitions for starting and displaying applications on both terminals. In response to external input to both terminals, the management block selects the application to be started and displayed. The management block identifies the terminal carrying the selected application, and transmits to the identified terminal a request to start the application and to switch display output accordingly.