More than 80,000 Canadian children undergo surgery each year. Despite evidence-based pain management and clinical standards, moderate to severe postoperative pain in children is common. Inadequate postoperative pain management contributes to poor health outcomes, increased opioid use, and the development of chronic postsurgical pain. Successful postoperative pain management requires regular monitoring and treatment of pain after hospital discharge. Smartphones are nearly ubiquitous, and growing evidence supports their use to overcome barriers to pain care. Computerized clinical decision support systems (CDSS) can improve pain self-management by tracking symptoms over time and offering tailored evidence-informed pain management advice based on standardized algorithms. A comprehensive and sustainable approach is needed to address poorly managed pediatric postoperative pain in the home setting. To address these gaps in care, we are developing "iCanCope with Post-Operative Pain" (or iCanCope PostOp), a smartphone-based CDSS app that provides remote, in-the-moment advice to improve pain and health-related quality of life (HRQL) for adolescents following surgery.