Zenbe is a very basic List app for $2.99 with a free web based component. My wife and I use it for Shared lists.
I use omnifocus as my primary GTD app, but I have found zenbe to be a very nice and simple List app.
I keep all of my lists in a single folder, but a person could subdivide by reference, project plans, etc.
Do you mean the basic "notepad" program that comes with a PC?
Depending on how many of these lists you have and how long they get....a fun little iPhone app is "Use Your Handwriting" or "UYH". Can be faster than typing on the iPhone keyboard.
I love mine for the shopping list, and also for the packing list, because you can check things off, but then go back later and "uncheck" them all to restart with a fresh list.