A smartphone app developed to pilot test a culturally tailored, bilingual (Spanish/English) lifestyle program to reduce risk factors for type 2 diabetes in Hispanic women with gestational diabetes mellitus (GDM) in the prior 5 years has the potential to fill the gap in care experienced by this patient population, according to study published in JMIR Formative Research. With a lack of mobile health programs to reduce these risk factors in this patient population despite the high prevalence of smartphone ownership these women, study investigators sought to develop the above-noted app (¡Hola Bebé, Adiós Diabetes!), examine its usability and acceptability, and assess its short-term effectiveness in increasing self-efficacy for healthy eating and physical activity and in decreasing weight. Features included in the app are educational audiovisual modules on healthy eating and physical activity; personal action plans; motivational text messages; weight tracking; user-friendly, easy-to-follow recipes; directions on building a balanced plate; and tiered badges to reward achievements. Statistically significant improvements were observed in selfefficacy for physical activity and for health eating, while weight decreased but not significantly. Data revealed a high level of user engagement and supported the app’s acceptability and usability.