Current research on physical activity among adolescents reveals that approximately 80% do not meet the recommended levels set by the World Health Organization. Recognizing childhood as a crucial developmental phase, it becomes imperative to prioritize health promotion during this period of the lifespan. Studies suggest that integrating gamification into mobile apps has a positive impact on adolescents’ physical activity levels. Furthermore, the incorporation of behavior change techniques (BCTs) has been recognized as a means to enhance the effectiveness of health-promoting interventions. Previous research indicates adolescents’ interest in BCTs such as goal setting/planning, feedback, reward, self-monitoring, social comparison, and social support. The objective of this particular study was to investigate the experiences of Swedish adolescents regarding physical activity and apps, with a specific focus on the influence of BCTs. The study involved three focus group interviews with a total of 18 participants aged 11–15 years. Data analysis was conducted using reflective thematic analysis. Participants in the study expressed positivity towards mobile apps that provide instructions, demonstrate behaviors, and explore the impact of removing rewards. Additionally, other appealing features of physical activity apps included the development of streaks, competition, and the provision of an appropriate level of challenge. This study significantly contributes to a deeper understanding of how BCTs and other features can be integrated into physical activity apps. It emphasizes that individualization and renewal may hold greater importance than the actual content features. These findings are pivotal for future efforts to develop interventions aimed at increasing physical activity levels among adolescents, not only in Sweden but also on a broader scale.