PURPOSE: To describe the process of developing an interactive home therapy technology and evaluate its usability with children. MATERIALS AND METHODS: Design thinking guided our technology development with knowledge holders. User- and theory-informed design needs were defined by empathizing with users through observation, interviews and literature review. Solutions were ideated through sketches that led to prototypes. Informal testing with knowledge holders was conducted before formal usability testing with 7 school-aged children (5 neurotypical, 2 with cerebral palsy). Children practiced exercises using the technology before completing a study-specific survey (5-point Likert scales and open-ended questions) that was analyzed using descriptive statistics and content analysis. RESULTS: Bootle Boot Camp, an interactive therapy game that enables clinicians to prescribe customized home exercise programs, was created. Through exercise videos, motion tracking, multimodal feedback that fades to summary, self-controlled form (i.e., star ratings) based on a child's performance, rewards and training resources, the game aims to promote safe and high-quality exercise according to design needs. Children found feedback helpful (mean 3.7/5) and audio cues easy to understand (mean 4.6/5). Users' recommendations to improve audio feedback delivery guided game refinements. CONCLUSIONS: Application of the design thinking methodology supported robust end-user involvement that facilitated development of a user-friendly technology.