“Master Knees” is the innovative Artificial Intelligence tablet application developed by Hong Kong Sheng Kung Hui Welfare Council, specifically for individuals with knee problems. Varied with their ability, users’ exercise intensity, frequency and cooling time would be adjusted accordingly. The App aims to strengthen users’ understanding of knee osteoarthritis, encourage them to establish a healthy exercise habit, and ultimately, become their own masters of their knees. It has incorporated features of “Exercise, Game, and Therapy”. With A.I. technology, the App could detect and record user’s movement and performance in real time. Through the camera lens of the tablet, it tracks and captures users’ posture and joint angle during the exercise, then match with the standardized data to generalize the ongoing scores. The matching scores give instant feedback all in real-time to users on their performance. Users become the player of the game and they have to finish all the prescribed exercises to clear a stage with higher scores. By the data record and skeleton figures, it could figure out the real-time exercise performance of users and fine tune their exercise prescription, so that they could obtain the most appropriate treatment and maximize its effectiveness.