Microsoft To-Do is an easy cross-platform tool for creating checklists. I use it to manage homework tasks and for breaking assignments into manageable sections. 

Because it is cross-platform you are able to set a task on your phone and sync it to your laptop. 

Lists can be created in different categories (work, home, club...), each entry can be tagged as important or in a "My Day" list.  
Any task can also be given a due by date which makes managing your tasks easy and helps me enormously with organising my day. 

See this FAQ to learn how to install To-Do.