Heart failure is a complex syndrome among older adults who may experience and interpret symptoms differently. These differences in symptom interpretation may influence decision-making in symptom management. A well-informed and motivated person may develop the knowledge and skills needed to successfully manage symptoms. Therefore, the patient-centered mobile health application HeartMapp was designed to engage patients with heart failure in self-care management by offering tailored alerts and feedback using mobile phones. The main objective of this article is to describe the six-step intervention mapping approach including (1) the initial needs assessment, (2) proximal program objective, (3) selection of theory-based methods, (4) the translation of objectives into an actual program plan for mobile health intervention, (5) adaptation and implementation plan, and (6) evaluation plan that assisted the team in the development of a conceptual framework and intervention program matrix during the development of HeartMapp. The HeartMapp intervention takes the information, motivation, and behavioral skills model as the theoretical underpinning, with “patient engagement” as the key mediator in achieving targeted and persistent self-care behavioral changes in patients with heart failure. The HeartMapp intervention is proposed to improve self-care management and long-term outcomes.