Mathematics is one of the core subjects in engineering education and forms the foundation of all disciplines in engineering. In Hong Kong, a significant number of students are admitted to engineering programmes without sufficient mathematical background. Engineering mathematics is essential for teaching and learning many fundamental and advanced engineering subjects. Due to this reason, a mobile application (app) is developed as one of the core components of engineering mathematics education by offering students flexible and self-initiated learning. In this study, a hypothesis model is proposed to investigate the effectiveness of student's learning in engineering mathematics with the developed mobile app. The results showed that the ease and convenience of using the mobile app have a positive effect on students' autonomous learning, and motivation and have a positive relationship with the learning effectiveness of the mobile learning (M-learning) app. It was found that the average marks of the assessment tests were significantly better than the screening test by using the app and notes. The current study has important implications in that the M-learning app should be used as a supportive role to supplement traditional teaching approaches.