Freemium ASTRID, available on iOS, Android, and via web, re-invents the to-do app by allowing public and group sharing of your everyday to-do's. It’s a perfect way to crowdsource collaboration, track project milestones, or incentivize certain tasks in a classroom setting with BYOD or 1:1 computing. Users may also invite friends via Facebook or Google, so if your school is running Google Apps for Education, setup should be painless. We imagine you could rig the same user experience in Evernote with some expertise, but Astrid makes scheduling, tracking, and updating super simple, and the free version packs a ton of functionality.