In Bangladesh, cholera poses a significant health risk to local populations. Individuals and households can reduce their risks of contracting cholera through safe water, sanitation, and hygiene behaviors and by limiting contact with potentially-contaminated water. Yet, as the Bangladeshi population faces both endemic and epidemic cholera, households may make suboptimal investments in cholera risk reduction if risk levels are unknown and unstable. If, however, households had access to early warning systems alerting them of periods of increased cholera risk in their communities, this information might shift their investments in risk-reducing behaviors such as boiling or filtering drinking water. We explore these ideas by developing a smartphone app to disseminate cholera risk information to households in Matlab Bangladesh. We develop two versions of this app: (1) an app with temporally and locationally specific cholera risk information--developed through a risk model that utilizes satellite data inputs--that is personalized specifically for an end user and (2) an app with publicly available information about averting cholera risk. We randomize access to each version of the app (as well as maintain a pure control group without access to either app) to measure whether providing personalized information about household cholera risk shifts cholera averting behaviors and cholera incidence within our study population. In addition, we examine the value associated with providing households with this type of personalized cholera risk information.