In the immediate aftermath of nature-based disasters such as earthquakes, fires, or floods, have a clear vision of the situation and the population involved is of main priority for rescue operations—it is a matter of life and death. But these disaster events may cause malfunctions in communication services making the exchange information impossible—the experienced delay sending a message in an overcrowded area is a shred of evidence. In this demo, we introduce Floater, a mobile awareness-based communication application for the immediate aftermath of a disaster, when ad hoc infrastructure support has not been deployed yet. Floater enables communications between peers in a common area without requiring the support of a cellular network. The application is developed for Android and it does not require an account or an Internet connection. Floater exploits local knowledge and constraints opportunistic replication (peer to peer) of information to build a global view of the involved area efficiently. The app is the first to implement Floating Content, an infrastructure-less communication paradigm based on opportunistic replication of a piece of content in a geographically constrained location and for a limited amount of time. The demo illustrates the feasibility and the main functionalities of Floater and presents disaster assistance use cases for supporting rescue operations.