This paper explores the impact of mobile device usage frequency in the classroom on students’ perceptions of their use. To assess this, we created a survey that measured students’ perceived frequency, usefulness, and convenience of using mobile devices, using a reversed Technology Acceptance Model. Through the analysis of responses from 781 Korean students, utilizing confirmatory item factor analyses and a structural equation mixture model, we found that the effect of frequent mobile device use on students’ positive perceptions is non-linear. As the frequency reaches to a certain level, the effect sizes of the frequency in the positive perceptions diminishes. Additionally, students who used mobile devices less frequently in class reported higher levels of difficulties in using the devices. This study introduces a tool for evaluating multiple aspects of students’ perceptions regarding mobile device use and offers a framework for understanding the relationship between usage frequency, usefulness, and convenience.