The majority of communication solutions for post-disaster areas rely on cellular infrastructure support. But disasters such as fires, floods, earthquakes, can disrupt communication network making its services unavailable. New portable antenna towers, as point-to-point radio communications, are a way to mitigate the communication when cellular infrastructures are unavailable. But their deployment requires time decreasing the likelihood of finding people alive in the following of such events. In this work, we present the architecture of Floater, a mobile application that implements opportunistic communication for context-aware services in post-disaster scenarios. Floater is based on Floating Content, an opportunistic communications paradigm that geographically constrains message replication. We implement Floater using Google Nearby API that enables seamless nearby interactions without having to be connected to the Internet. Moreover, we provide the implementation notes and the comparison of the technologies adapted with the respect of the state-of-the-art.