Online Nurse Test for Indonesian Nurse Competency (ONT UKNI) is a mobile application that was developed to help increase the success rate of nurse competency test participants. By using this application, users can learn more about the materials tested and conduct try out as a competency test simulation. However, ONT UKNI has not yet passed adequate testing stages, especially in terms of User Interface/User Experience (UI/UX). The Covid-19 pandemic situation presents challenges in the UI/UX testing process. Testing process which is ideally carried out face-to-face with respondents to get further insight, have to be carried out using another approach following the new normal protocol. This study aims to test the usability of UI/UX with an unmoderated remote testing approach on ONT UKNI application using a USE questionnaire. The test was performed using 26 respondents and all were nursing profession students of Universitas Muhammadiyah Yogyakarta. Respondents performed 8 tasks on ONT UKNI and answered set of questionnaire that will be tabulated and analyzed. The results indicate that usefulness, ease of learning, and satisfaction variables get the Very Good category while the ease of use variable gets the Good category. Overall, usability testing using an unmoderated remote testing approach can be carried out and able to provide information about areas where users are satisfied with ONT UKNI application. However, some areas still have room for improvement such as better UI design and implementation of gamification.