The development of information technology has brought significant changes across various sectors, including the field of User Interface (UI) design. UI development is crucial to ease the use of an application for users. The Guidofiks application, designed for vehicle diagnostics, is created with a user-friendly UI. This application utilizes an On-Board Diagnostics (OBD) system to monitor vehicle performance in real-time. The Agile method and Scrum framework are used for the UI development of the Guidofiks application, involving user stories, product backlog, sprint planning, sprint execution, and sprint review. Nine main items were identified in the product backlog to be developed by the team. Some of the resulting items include login, registration, homepage, diagnostic feature, profile page, breakdown probability feature, community feature, nearest workshop feature, FAQ page, and feedback. The Agile approach in Guidofiks has proven effective in enhancing responsive development to changes. Although still in prototype form, the next project is expected to fully implement Agile, resulting in a complete software product.