By downloading the iTunes U application, students can access their courses using their iPhone, iPad, or iPod Touch.
According to Apple, "If you’re an educator at a university, college, or K-12 school, now you have an easy way to design and distribute complete courses featuring audio, video, books, and other content. And students and lifelong learners can experience your courses for free through a powerful new app for iPad, iPhone, and iPod touch."
"The free iTunes U app gives students access to all the materials for your course in a single place. Right in the app, they can play video or audio lectures. Read books and view presentations. And when you send a message or create a new assignment, students receive a push notification with the new information."
Get more info: iTunes U app