A number of studies have shown that health literacy is an important factor in a variety of health status indicators and outcomes. Low health literacy differentially affects minorities and older adults, but can be addressed through effective educational interventions. Even when provided in groups, however, these interventions can reach only a small number of individuals. Mobile applications can be widely deployed and can improve individuals' health literacy. In this article we discuss strategies for determining the optimal level of health literacy at which to intervene and suggest specific instructional strategies for various levels of health literacy.