If the app behaves unexpectedly, try to uninstall and reinstall the app. Make sure after you press "New Plan" to close your app from the multi-tasking and restart it. If there happens to be bug, then let me know.
There are "+" buttons in each quarter for each year. You can choose your course from the list or you can search for the course through the search bar. There isn't every course so if it is not, then you can always "Add Course" in the top right corner to add a custom course.
At this time, I haven't added the feature for a sixth year; however if more people request it, I will be glad to add it.