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 in these women, study investigators sought to develop the abovenoted 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. App features include are educational modules on healthy eating and physical activity; personal action plans; motivational text messages; weight tracking; recipes; and tiered rewards. Statistically significant improvements were observed in self-efficacy for physical activity and for healthy eating, while weight decreased but not significantly. Data revealed a high level of user engagement and supported the app’s acceptability and usability.