Background: Breastfeeding coverage in Indonesia is still low, including Padang City, especially in the Andalas Health Center working area, which is 51.1%, has not reached the national target of 90%. Self-efficacy is one of the main factors in increasing exclusive breastfeeding behavior. Self-efficacy is influenced by the mother's knowledge about how to overcome breastfeeding problems. Increasing knowledge can be done through the innovation of complementary therapy disc applications that can be accessed by mothers via Android. Objectives: This research aims to determine the effectiveness of implementing the cakoASI.id application on the self-efficacy of breastfeeding mothers in overcoming problems in breastfeeding. Methods: This research uses a pre-experimental design method with a one group pre-posttest design approach. This research will be carried out for six months in the Andalas Community Health Center working area. The sample in this study was breastfeeding mothers with babies aged <6 months. Purposive sampling technique will be used to determine the sample. The instrument that will be used is a questionnaire to determine self-efficacy. This research will be carried out within one year. The research results will be processed using the paired T test statistical test. Results: It was found that the mother's self-efficacy before was 41 and after was 59.8 with a p value of 0.000 (p≤0.05) which means that there is an influence of the use of the Android-based application intervention "cakoASI.id" on the self-efficacy of breastfeeding mothers. Conclusion: There is an effect of using the android-based application intervention "cakoASI.id" on the self-efficacy of breastfeeding mothers.