You can scribble in 6 colors, 3 thicknesses, and you can also erase. There's undo/redo options, which is a pleasant surprise.But the more important detail is that the curves are smoothed out, which is more than I can say for most sketching apps.
Sharing options include emailing the current page, saving it to your photo album, and printing the page. You can also email an entire notebook as a PDF or print it. Curiously enough, the free app appears to only have the one notebook. This is going to cut into my ability to organize.
The one downside for this app is that it really wasn't designed for a fingertip. It requires a finer degree of control than I'm used to using on the iPad. Apps like this are why I got a stylus for my iPad. I don't know anyone else who has one but I also knew it was a good idea.
BTW, Wacom are using the free app to promote their. Trust me, you don't need to spend that much. You can find quite adequate styluses in the $5 to $10 range.