Background: Acclimating to a new technology device, such as a continuous glucose monitor (CGM), can be challenging. Current resources may not sufficiently answer questions patients living with diabetes (PWD) may have. We asked how we might improve the process to onboard a PWD to CGM. Our specific aims were (1) to develop, employing a co-designing approach, a prototype of an app for facilitating onboarding to CGM and (2) to obtain early feedback on its usability. Methods: We applied a human-centered design (HCD) approach; this process first seeks to deeply understand the unmet needs and frustrations users face. After wearing a demonstration CGM; observing PWD onboarding with health care professionals (HCPs) in clinic; and interviewing 8 PWD and 2 HCP, we developed, tested, and refined a low-fidelity prototype of a clickable app. With insights from this initial round of feedback, we then created a high-fidelity prototype with 3 key features: (1) individual entry of goals and questions; (2) a daily progress tracker for these goals; and (3) a community portal that facilitates exchange of questions and answers. We used the validated System Usability Scale (SUS) to quantify user feedback. Results: Focus group participants found our early app to be usable and acceptable. Measurement of usability by the SUS yielded a score of 74, which is above average (68) reported for all applications tested, per usability.gov. Conclusions: Our early prototype app is a more personalized, additional tool that could bridge an information and support gap for patients who are new to CGM. This app could also help PWD on an ongoing basis, by evolving with them to enhance ease and engagement with diabetes self-management.