App function
The app is relatively simple with text messages and library information. Another app developed for increasing breastfeeding among African Americans had almost the same technological components and had above-average usability [We understand that the interactive app feature is of interest and may increase engagement. However, we decided to not develop an app for monitoring the child’s growth, albeit it was one of the most preferred features reported by mothers. There are additional privacy considerations with receiving detailed information of this type. As we targeted to improve exclusive breastfeeding rates, the app was designed for mothers’ use until 6 months after birth. At this stage of development, attention to the increasing weight of an infant may drive a mother to formula feeding, whereas the public health emphasis is on overall development [Often mothers do not manage exclusive breastfeeding due to unsolved difficulties in breastfeeding. Therefore, emotional support along with providing appropriate knowledge is very important for lactating mothers. A function of mutual communication between a mother and lactation counselors built into the app is ideal. However, there is a lack of lactation counseling services in Vietnam so we cannot build this function.