This paper addresses the persistent challenges children with autism and other disabilities face in engaging with regular physical activity, a factor strongly linked to long-term health outcomes. Many existing interventions rely on rigid rehabilitation methods that fail to sustain motivation or adapt to individual needs. To overcome this gap, we propose a mobile application that combines exercise tasks, gamification, and AI-generated storytelling. Built with Flutter, Firebase, and the ChatGPT API, the system integrates three components: secure authentication and profile management, personalized storytelling to enhance engagement, and a reward-based progression system [12]. Major challenges include ensuring age-appropriate content, balancing extrinsic and intrinsic motivation, and maintaining secure data storage. Experiments tested the personalization accuracy of AI-generated stories, revealing significantly higher engagement compared to generic narratives. The results highlight the importance of detailed profiles and adaptive feedback. Ultimately, this project demonstrates a scalable, inclusive, and enjoyable approach to motivating healthier lifestyles in children with disabilities.