Due can be used to keep track of things you have checked out, things you have to do by a certain date, and more. Its features include color-coding and sorting by due date or warning date.
Not even sure I should be reviewing this, as I'm using it for another purpose, which is for a regular TO-DO list. But no other To-Do list would really do what I wanted it to, and since this orders items by date due, I simply change the due dates to reorder the list. The interface is really attractive, to; a big plus.