To the Editor We read with interest the research letter by Cohen and colleagues1 that described a mobile application (app) to provide peer-reviewed education to individuals with acne and to identify users’ characteristics. As noted in the research letter1 and accompanying commentary,2 mobile apps have significant potential to provide information to large numbers of dermatology patients. However, these apps can and should go far beyond the role of surveying users and providing information and basic education.3 Dermatology apps should use evidence-based approaches and sophisticated programming to facilitate the promotion, inhibition, and self-monitoring of behaviors (eg, treatment adherence, UV exposure and protection, skin self-examination, and diet), symptoms, and other important outcomes (eg, quality of life). Additionally, apps can provide content that is tailored (ie, personalized to individuals’ behaviors and other characteristics), customized (ie, incorporating user-selected features or content), interactive, and dynamic, which may facilitate user experiences, engagement, and attainment of targeted outcomes. Apps can harness the myriad functions of smartphones and tablets, including taking photographs, video conferencing, text and multimedia messaging, instant messaging, and geographic locating (via global positioning system [GPS]).