Mobile health apps are often used between appointments by physiotherapy patients to improve post-surgery exercise compliance during rehabilitation. This paper describes the development process of such an app incorporating the 4 stages of Design Thinking [3]. The app works as an intermediary between physiotherapists and post-op patients to encourage, motivate and monitor their rehabilitation process and ensure that it is adhered to. The process started with initial questionnaires with physiotherapists and patients. Needs and solutions were identified and five concepts were then developed. These were the colour scheme, exercises, gamification, interactive features and user aspects such as signing up, profile and the rehabilitation plan. After this low and high fidelity prototypes were developed in Wireframe and Figma. Subsequent questionnaires were used to elicit user feedback during prototype development. The final app included sections such as “My Rehabilitation Plan” through to “Health Benefits”, “My Community”, “My Progress”, “My Motivation”, “My QR Code” and “My Feedback“/Notes”. Participants were generally favourably disposed towards the App, stating that they would be interested in its continued development, giving it an average score of 5.7 on a 7-point Likert scale.