iPad: Need to sketch while you take notes? Then download Paper from FiftyThree right now. The app is free and it gives you digital notebooks to capture all your ideas quickly and intuitively.
Getting started with Paper is quick. Tap on a notebook and start sketching, writing or outlining quickly with the free drawing/pen tool. You can swipe and pinch to move between pages in your notebook as well. If you need additional tools, they are available for $1.99. Pencil for sketching, marker for outlining and watercolor paintbrush.