The Pencil stylus, from the folks at Fifty Three - the team behind one of the best known iPad apps, Paper. The flat stylus is like one I haven't seen before, yet super comfortable in the hand. It features a touch-sensitive tip and eraser end.
The two-ended stylus actually activates three tools when connected to the app. Users can quick sync by touching the tip of the stylus to the stylus icon in the toolbar of the app, which syncs it up and makes it ready to use. The narrow tip draws using the selected tool while the broad end acts as an eraser, just as one would naturally expect. The third feature is the smudge tool: when the stylus is activated, using the tip of a finger on the screen smudges what is touched.
The tip of the stylus moves smoothly over the screen and the app reacts quickly. The eraser is natural and easy to use. Flipping the stylus over to erase seems so natural. Response time is very quick and accurate on the Retina iPad mini I tested it on.
The big downside to the Pencil stylus is that it only fully works with the Paper app. FiftyThree hasn't announced any sort of SDK to allow other apps to add support for the stylus. If not previously purchased, activating the stylus in Paper will unlock the tools that normally require an in-app purchase.
Use of the stylus feels very natural, which I think I've mentioned more than a couple times already. That's the design genius in this stylus. Pick it up and the user instantly know how it should be used. The hand feel is nearly perfect, though I prefer a slightly heavier stylus.
Highly Recommended