Abstract Background Despite strong evidence about the benefits of exclusive breastfeeding, that is the baby receiving only breast milk, no other foods or liquids, rates have remained relatively unchanged over the past two decades in low- and middle-income countries. One strategy for increasing exclusive breastfeeding is through community-based programs that use peer counselors for education and support. The use of mobile health applications is also gaining increasing applicability in these countries. Minimal information is available about training peer counselors in the use of mobile technologies to support exclusive breastfeeding. The present article describes our curriculum in the state of Karnataka, India for supporting new mothers to exclusively breastfeed using a mobile health application in rural India. Methods Twenty-five women from the community surrounding the city of Belgavi, Karnataka, India were trained to be peer counselors and to use a mobile health application to conduct a structured curriculum to support new mothers in exclusive breastfeeding. The three-day interactive training, conducted in March 2018, was based on the WHO breastfeeding course, translated, and adapted to the local culture The curriculum, which included information collected during a formative research process, consisted of eight visits, two during the antenatal period and continuing for six months postpartum. Twelve nursing and obstetric experts validated curriculum content. Pre-post-evaluation of the training focused on breastfeeding knowledge, self-efficacy, skills, and app usability. Results We observed a significant increase in the mean scores for knowledge (P < 0.0001) and skills (P = 0.0006) from pre- to post-training. Age of the peer counselors and their own breastfeeding experience correlated significantly with the acquisition of knowledge and skills. The mobile health app showed high usability scores. Conclusions The culturally adapted curriculum presented here, combined with an mHealth app, can be an important educational strategy for training rural women in the acquisition of exclusive breastfeeding knowledge and skills.