This study plans to learn more about how to increase postpartum weight loss and how to decrease risk factors for postpartum women at increased risk for diabetes and heart disease. The program is delivered using a mobile application (app) and a lifestyle coach. This mobile application is developed for women who are at higher risk for diabetes and heart disease. Women who have gestational diabetes, (diabetes during pregnancy, or GDM), gestational hypertension (high blood pressure), and/or preeclampsia (high blood pressure and protein in the urine), and/or small-for gestational-age, and/or preterm (early) delivery during their pregnancies have a higher risk for diabetes and heart disease. This mobile application was developed using the latest research studies and using the evidence-based Diabetes Prevention and Colorado Weigh programs. The goal of the program is to help women lose weight and participate in physical activity after delivery.