Exposure to air pollutants is a significant health risk for individuals with asthma, cardiovascular disease, and chronic obstructive pulmonary disease. Measures such as limiting time outdoors or performing less strenuous tasks when air quality levels are better can mitigate these risks, but only if people are aware of both these recommendations and how to know when air quality is best, and worst. Formative audience assessment determined that applications developed for mobile devices are the optimal way to provide this information, but knowledge of the existing United States Environmental Protection Agency (EPA) and partners' AirNow tool was minimal. We developed, field-tested, adapted, and implemented pilot efforts at both the national and local levels to address this knowledge gap, and present findings suggesting a concentrated local effort can heighten use of AirNow, leading to more pro-healthy behavior.