Free typing tutor iPhone app

I have been looking for a free iPhone typing app in the Apple iPhone app store and haven't had much luck finding one. The reason why I want to find an app like this aside from the obvious desire to increase my typing speed is to help improve my typing accuracy. You'd be surprised to discover how much time is wasted clicking the back button. I think that having an iPhone typing tutor app will help increase accuracy which will then increase typing speed by reducing the amount of time spent clicking the back button. So if you know of a nice typing tutor app for the iPhone, drop a comment and let me know.