Self-management Digital Intervention to Promote Physical Activity in People Living With COPD

The goal of this pilot randomized controlled trial is to evaluate the feasibility, acceptability, and preliminary effects of a theory-based self-management digital intervention (Respir'air BPCO) designed to promote physical activity in patients with Chronic Obstructive Pulmonary Disease (COPD) after completion of a pulmonary rehabilitation program. The main question it aims to answer is: Is the Respir'air BPCO intervention (mobile app) feasible, acceptable, and preliminarily effective in increasing physical activity, enhancing self-management, improving motivation, and quality of life, while reducing dyspnea severity, exacerbations, and hospitalizations, compared with no additional intervention? Researchers will compare an experimental group (receiving the Respir'air BPCO intervention + usual care) to a control group (no additional intervention, only usual care) Participants will: Be assigned either to the control group, receiving no additional intervention beyond usual care (traditional pulmonologist follow-up), or to the experimental group, receiving access to the Respir'air BPCO mobile app in addition to usual care. * Complete baseline assessments immediately after finishing their in-person pulmonary rehabilitation program. * Complete follow-up assessments at 3 months and 6 months after the start of the intervention