Systems and techniques by which a single electronic device can implement a variety of customized control interfaces. The control interfaces can be tailored to specific operations performed the device which is controlled. In one aspect, computer-implemented methods for controlling a web-based application include providing, from a server, a web page that includes a web-based application and a uniform resource identifier specifying a control interface for the web-based application and transmitting the control interface specified by the uniform resource identifier to a client for use in controlling the one or more functions of the web-based application. The control interface is configured to permit a user to control one or more functions of the web-based application from a mobile device.