This paper proposes the design and implementation of a system for simultaneous communication of several users over a single display, such as large public displays or video walls. Motivated by the lack of software frameworks that are both free and suited for the desired level of complexity, we present a novel, out-of-the-box solution for collaborative and remotely controlled application use. The solution is based exclusively on web technologies, thus significantly facilitating usability and reach, and eliminating the need for additional software installations or the use of additional devices. The architecture of the developed solution is modular and comprises three main components: (1) the environment, (2) the remote controllable application (RCA), and (3) the controller. The environment serves as a central hub that manages the data flow and ensures synchronization between the user devices. The RCA, which runs on the large display, serves as the interface for interacting with the content, while the controller, which is loaded on the users’ smartphones, enables control and interaction with the RCA in real time. By using web sockets and a server–client architecture, the system supports device- and platform-independent remote control and centralized collaboration through an off-the-shelf communication framework entirely flexible regarding client application. In order to demonstrate the possibilities of the proposed system, several different scenarios were covered, and solutions were implemented and tested on a large display in the faculty lobby.