Participatory design (PD) is an emerging alternative to existing methods of user-centered design (UCD), and may be a more appropriate approach for designing patient-facing products in the health care sector than conventional UCD. Type 2 Diabetes Mellitus (T2D) is a serious chronic illness that requires life-long treatment and life-long self-management of food intake, physical activity, and self-testing to avoid complications. T2D disproportionately affects low-income minority communities. Using PD, we have developed an app to help T2D patients. Called the Diabetes Networking Tool (DNT), the app is intended to help patients better self-manage by empowering their network of family and friends to better contribute and support the patient's self-management needs. PD was used to involve a low-income African American community into the process of identifying the specific problems and issues DNT needed to address. We then used multiple complementary analytical methods to condense and abstract the community inputs to yield a functional and user interface design for DNT.