Public Screens are widely used in modern cities in the fields of public transportation, commerce, education and advertising. They respond to users' inputs passively rather than spontaneously interacting with them. Therefore few screens are sociable. This situation has started to change with the progress of interaction technology. In this paper we present an application independent proxemic platform, which includes a sociable public screen together with a file migration toolkit. The sociable screen displays information according to user's distance, orientation, posture, location and identity. Moreover, via the toolkit we can exchange resources easily and safely between various ambient devices with the screen. The platform works as a public sociable medium connecting citizens and providing new opportunities for them to communicate with each other. We describe the platform application using a bus shelter scenario before demonstrating the usability of our work through user study.