I got started with Paper for the iPad about a year and a half ago, and this week the popular drawing and sketching app received an update for iOS 7 that includes two new features that provide finer, more creative controls.
First, the size of your brush or pen strokes are smaller when made inside the loupe. Pinch out to call up the loupe, which magnifies a portion of the page. Prior to this week's update, your pen strokes would be huge inside the loupe, which defeated much of its purpose. Now, the bigger you make the loupe, the finer your strokes become, giving you much greater control over your drawings.
Second, you can embrace your inner Georges Seurat and make beautiful pointillism creations. Now, when you tap with the fountain pen or eraser tools, the longer you hold down your finger, the larger the resulting dot.
Paper is free, but many of its tools are available only as in-app purchases.