The aim of this clinical trial is to determine the effect of a mobile-compatible web-based gamified application (Game-App-KNEE) developed for post-operative care of total knee replacement (TKA) surgery on functional outcomes and recovery status. Based on this, the hypotheses of our project are; In the intervention group where the mobile-compatible web-based gamified application to be developed for the home care of individuals undergoing TKA due to osteoarthritis is applied, compared to the control group; Hypothesis 1 (H1): After the application of Game-App-KNEE, the functional levels of individuals in the intervention group are higher than the control group. Hypothesis 2 (H1): After the application of Game-App-KNEE, the post-operative recovery levels of individuals in the intervention group are higher than the control group. Participants: Receive the game module application (intervention group) or only the educational booklet (control group) every day for 3 months after discharge Visit the clinic every 1st and 3rd month for check-ups and tests.