Using a Design Thinking and co-design methodology, hospital staff and consumers developed a novel mobile health app for heart failure self-management. Various stakeholders engaged in three development stages: interviews, design workshops and prototype iterations. Eleven of 18 co-design team members reflected on the co-design process and design outcomes. A total of 144 data points were collected: 96 about the co-design process and 48 about the design outcomes. Successes and failures reflect the strengths and weaknesses of operationalising codesign in practice. Overall, participants were surprised the design outcomes were achieved. The app was considered a supportive tool for meaningful self-monitoring and patients believed the app would be applicable to their situations. Our findings suggest that local co-design can be achieved through meaningful partnerships, and managing stakeholders was key to the project’s success.