Digital sticky notes for which you can add check list features, reminders, etc., with the ease of a click of the mouse...a most welcome tool!
On different notes, in different colors and in even in different styles (skins), I keep track of my To Do Lists. On one, I track my household tasks, while on another, I list grocery items and cleaning supplies.
With a busy schedule, I welcome tools that help me maintain focus, assist me with staying on target, and that provide a satisfying record of completion.
The non-cloud version of Notezilla for Windows is sold at a reasonable price and has been more than worth cost in helping me stay on task. It's a simple, visual method that mimics an old school reminder method in a new, elegantly digital way.