I've made this addon because I kept having thoughts like "I need pet food" and didn't get any in the end.
My addon will keep track of this, and notify you every so many (pre-specified) seconds.
Slash commands:
/tdl
/todolist
Don't forget to press "Save" after adding a new item to the list. If for some reason the addon did not automatically load your list (at startup, or w/e) you can use the "Load" button