With the advances in mobile technology, mobile learning has gained importance and has spread widely especially among young people. In this study, a research model is developed to determine the factors affecting the usability of a mobile learning application belonging to one of the most popular MOOCs (massive open online courses) providers. The constructs—aesthetic graphics, color, control obviousness, entry point, fingertip-size controls, font, gestalt, hierarchy, subtle animation, and transition—adapted from the study of Hoehle et al. are included to reveal their effects on usability perception. Furthermore, the operating systems—iOS or Android—used in the mobile devices affect the usability of the mobile application is explored. A questionnaire is developed, and 223 surveys are collected from the users of the application. The results of the study show that gestalt, control obviousness, subtle animation, and aesthetic graphics are significant factors on the usability perception of the users.