Online courses provide students flexible access to class at anytime and anywhere. Most online courses currently rely on computer-based delivery. However, computers still burden instructors and students with limited mobility and flexibility. To provide more convenient access to online courses, smartphones have been increasingly adopted as a mobile method to access online courses. In this paper, we share our practical experience in designing and developing a smartphone platform for accessing online courses. The main contributions of this paper include: (1) we present the main technical issues of applying smartphones to online courses; (2) we discuss several key factors of designing, developing and delivering online courses that support smartphone access.