Introduction Breastfeeding is critical for infant health, offering numerous physical, emotional, and developmental benefits. However, breastfeeding rates remain suboptimal globally, including in the Philippines, due to misinformation, cultural misconceptions, and inadequate healthcare support. Nursing students, as future healthcare providers, play a pivotal role in promoting breastfeeding practices. This study explores the use of LactApp, a mobile health (m-Health) tool, to enhance nursing students' knowledge, attitudes, and practices regarding breastfeeding. Methods A sequential explanatory mixed-methods design was employed, consisting of two phases. In Phase 1, 135 nursing students from the second, third, and fourth years completed a pre-test survey to assess their knowledge, attitudes, and practices regarding breastfeeding. After utilizing the LactApp tool for three months during their clinical placements, participants completed a post-test to evaluate changes in these areas. Quantitative data, including assessments of the tool's effectiveness and barriers to its use, were analyzed using paired t-tests. In Phase 2, a subset of students participated in semi-structured interviews to explore their experiences and perceptions of using LactApp. Qualitative data were analyzed through thematic analysis to identify key themes and insights. Results The pre-test and post-test surveys indicated significant improvements in students' breastfeeding knowledge, attitudes, and practices after using LactApp. Qualitative interviews revealed that students found LactApp easy to use and valuable in supporting their clinical work. However, some barriers to its use, including technological issues and resistance from mothers, were identified. Students also expressed positive perceptions of incorporating digital tools, like LactApp, into their nursing curricula. Conclusion The use of the LactApp tool effectively enhanced nursing students' breastfeeding knowledge and practices. The integration of m-Health tools in nursing education shows promise in bridging gaps in breastfeeding education and empowering students to support breastfeeding mothers effectively. Future research should focus on overcoming barriers to digital tool integration and expanding its use in nursing curricula to improve maternal and child health outcomes.