The C3PO project promotes the development of a new kind of spontaneous and ephemeral social networks dedicated to cultural, festive or sports events. They rely on opportunistic communication networks formed dynamically by mobile devices carried by event attendees. In this paper, we present both the opportunistic communication framework we have designed in project C3PO and the Android mobile application we have developed using this framework. We also propose a demonstration, where we will invite conference attendees to use our Android mobile application to cover the CHANTS’15 workshop by exchanging multimedia contents during this event. Categories and Subject Descriptors C.2.1 [Network Architecture and Design]: Store and forward networks Keywords Mobile Social Networking; Opportunistic Networking.