The co-design of a mobile health (mHealth) application for family caregivers of people with dementia to address functional disability care needs is presented. Participants included family caregivers of people with dementia, aged care nurses, physicians, occupational therapists, and information technology (IT) experts. The co-design process involved two phases: (1) needs assessment phase (an online survey and in-depth interviews with family caregivers and expert consultation); and (2) development of an mHealth application (content and prototype development). Data triangulation from phase one informed the content of the application. Data triangulation resulted in three content modules: “an overview of dementia and care,” “management of daily living activities,” and “caregivers’ health and well-being.” The content was based on contemporary literature, and care guidelines with input from family caregivers and dementia care experts. IT engineers developed the mHealth application. In this study, an Android-based mHealth application was designed to address the functional care needs of family caregivers and the co-design process ensured the incorporation of end-users’ real-world experiences and the opinions and expertise of key stakeholders in the development of the application prototype.It is to be noted that before releasing the application into the app store, testing its feasibility and effectiveness is essential.