The widespread use of smartphones in the United States has led to a surge in mHealth apps designed to support people with various health issues. Yet the effectiveness and long-term impacts of these apps still need to be determined. This article presents a case study of the development of MyT1DHero, an mHealth app for people with type 1 diabetes, to identify best practices for app development. We propose four essential best practices based on the insights gained from this case study: incorporating theoretical frameworks, prioritizing user feedback, engaging key stakeholders, and establishing a robust data-collection foundation. These findings have practical implications for researchers and developers seeking to create effective mHealth interventions. Furthermore, we suggest future research directions to advance the development and implementation of innovative health technologies.