ArabEasy is an application to learn and understand basic concepts of Arabic. This app has a problem with the user interface (UI); based on the comment from users, UI this app is confusing to use. This research focuses on measurement and testing based on usability level using the PACMAD model. Data collection was obtained from Performance Measurement, SUS Questionnaire, NASA-TLX Questionnaire, and RTA Questionnaire. The result from this process is measured using usability metrics, statistical testing,  and calculation from the questionnaire, respectively. The next process, making a recommendation to improve UI, became a prototype based on The four Golden Rules of User Interface Design. The result of this process showed increased effectiveness 37.22%, efficiency 46.08%, satisfaction 24.25. Furthermore, errors aspect decreased 13.4%, and the cognitive load 18.54.