https://marco.org/2008/08/26/watch-in-hd-on-vimeo-instapaper-pro-is-now
Instapaper Pro is now available!
This video demos one of the key features: tilt scrolling. Pro also remembers your positions in each article and has adjustable fonts. See other features of Instapaper Pro.
(If you buy it, please leave me a quick review in the App Store, positive or negative — I’d rather the reviews come from actual users than random passers-by in the store who didn’t actually buy it. Thanks!)