This app allows you to view and share, in real time, observations of floods and their effects. It also allows you to send information about other related phenomena, places where there is a potential flood risk, evidence of historical floods, significant infrastructure or emblematic sites related to flooding. The information compiled through the app may be consulted via the app or the web page of the FLOOD-UP project (www.floodup.ub.edu). This information is very valuable for researchers as a source of data on the impact and perception of floods and resilience to flooding across the country. It has the additional benefit of enabling us all to increase our knowledge of natural hazards that occur in our territory. The app also provides educational guidelines for learning more about flood risks and prevention tips and links to further information. floodup is an application developed by the Meteorological Hazards Analysis Team (GAMA) from the University of Barcelona Department of Astronomy and Meteorology. This application forms part of the UB mobility project. “FLOOD-UP. Exploring our resilience against flooding” is a scientific outreach and citizen science project about the risk and impact of flooding funded by the Spanish Foundation for Science and Technology (FECYT) – Ministry of Economy and Competitiveness (MINECO). Sending photos implies acceptance and approval of their reproduction under the Creative Commons license (CC BY-NC-SA, https://creativecommons.org/licenses/by-nc-sa/3.0/deed.en), with recognition of authorship. Remember that you should NEVER put your life at risk to take a photograph.