iNoteIt is a fairly standard note-taking app for the iPhone that doesn't offer a ton of features, but is free and very quick -- making it a good download for anyone seeking an easy way to jot down thoughts or to-do lists. The app's opening tutorial is perfectly designed to show you everything you'll need to use it effectively, and it's always very quick and responsive, making for a decent all-around app.
When you open iNoteIt there will be five notes already on your list. Each of them shows you how to do one thing in the app. You can tap an item to open it and edit the text, swipe to the right to delete it, or swipe to the left to complete it. You can also hold down each item to move it in the list and adjust priority. All of these things are very intuitive and allow the developers to keep it all on one screen, a very smooth interface for an app like this. Combined with the clean, open interface, the fast response time when opening and when creating new notes, and the handful of options for adjusting your notes, it's a great little app.
If you need a free note-taking app for your iPhone, consider downloading iNoteIt. It doesn't have some of the more advanced features of a GTD app, but it is free, fast, and very responsive. Combined with a clean, iOS 7-ready interface and plenty of tools to keep your list organized, it's a good pickup for anyone with light tracking needs.