Thanks, Jilly! I use Simple Mind X on the iPhone. It's a free app (there's a paid app, too--I think without the X, but I've never used it; this one works great for me)& it's very easy to use. Basically, you just click a plus button to add things and you can move stuff around with your finger. Plus, it has several style options--I like the bright colors one.
I keep my running grocery list, errands list, etc. on there. It's also good for jotting down ideas for articles, etc. when you're out & about.