The Mobile Intensive Course (MIC) application version 2 is an application designed to assist the learning process of the English intensive course subject. Measurement of the application usability has never been done before, so the effectiveness, efficiency, and user satisfaction for this application have not been measured yet. Also, usability measurement can be used as a reference for the level of user loyalty, whether it is net promoters, passive users, or detractors. One of the usability measuring tools that are easy to use but still valid and reliable, is the System Usability Scale (SUS). The purpose of this study was to test the usability of the application to determine the quality using the SUS questionnaire. This research was conducted in four steps, namely 1) trying out the application to the respondents; 2) distributing SUS questionnaires; 3) calculating the average SUS score; 4) analyzing the average SUS score. This study involved 37 respondents consisting of students and EIC lecturers. The results of this study indicates that the usability of the application can be accepted by users with an average SUS score of 70.61 and obtained C mark based on the CGS assessment. Nevertheless, the application only obtained passive users. The average contribution value for learnability was still low, namely 1.9 from the maximum score 4. It is necessary to improve future applications in terms of application learnability that allowing users to be more familiar with applications and potentially becoming net promoters.