I'm not a college student anymore, but I can vouch for Grades being an app that any smart high school or college student would have on their iPhone. It sets you up to succeed, letting you know what you have to score on your next test to maintain an A. With your syllabus in hand, you can setup each of your classes with homework, project, quiz, and test fields with respective weights. Once the teacher gives you your grade, all you have to do is add it to the app. You can read more about it in my review of Grades 2.
Grades 3 is now a full fledged day planner, replacing expensive notebooks from the campus bookstore with an all-in-one contact lists, reminders, and even a place to put important notes (useful for copying down assignment or project info scribbled on the board). Grades 3 provides the bird's-eye view students need to stay on top of their assignments and due dates.
For a limited time, Grades 3 is just $1.99 from the App Store. Currently designed for iOS 6, an iOS 7 specific update is forthcoming.