Evernote is a very good notes app, syncs between lots of devices.
However, using Evernote for ToDo list is not a standard approach. ToDo items can be spread across multiple notes, so you might have to use a saved search to see all notes with a checked or unchecked todo item.
I actually like this method, because the notes provide context for my ToDos, but it did take some getting used to (compared to traditional todo list manager apps)