I just learned about Assignment Planner from Edudemic. Assignment Planner is a free app for Android that keeps track of assignments, homework, projects, course and class information, and grades. It includes the ability to sort assignments by due date or course and set reminders for assignments. It's easy to use and got excellent reviews. (Here are some more apps for students for notes and class planning)
The free version has ads (at bottom of the screen - never bother me on my ad supported apps) but the pro version with no ads is only $1.29.
This is a great resource for students to stay organized in school and not forget about things.
Check it out in the Google Play app store and on Facebook.
10 Great, Free Apps for Students for Notetaking and Class Planning
Evernote - notetaking, web clipping, and more, on any device
Comparison of some popular note taking apps
Getting Students and Teachers Organized - tips and resources - includes links and resources for electronic and paper planning
10 Things Students Use Technology for in my Class