At Berkeley, couple of students built a web app for generating schedules automatically (Ninja Courses[1]). Now, this isn't entirely analogous to this app: they didn't charge students for using the program and it only plans your schedule; you have to actually register yourself. However, it does access very similar information like how full classes and sections are.

Instead of shutting them down, the university licensed the technology and now provide a Berkeley-branded version [2].

[1]: http://ninjacourses.com [2]: http://schedulebuilder.berkeley.edu