In low- and middle-income countries (LMIC), community health care workers (CHCW) are the primary point of care for millions of people. Mobile phone health applications (mHealth app) are the preferred technology platform to deliver clinical support to CHCW. In LMIC, limited regulatory oversight exists to guide quality and safety for medical devices, including mHealth. During the development of a mHealth app to assist CHCW with patient assessment and clinical diagnosis in rural South Africa, we applied human-centred design (HCD) and a bioethics consultation. The HCD approach enabled us to develop a mHealth app that responded to the needs and capacities of CHCW. The bioethics consultation prompted early consideration of safety concerns, social implications of our mHealth app and our technology's impact on the CHCW-patient relationship. In this study, we found that combining a HCD approach with bioethics consultation improved the design quality and reduced safety concerns for our mHealth app.