I was intrigued enough by your description to try this out. The video demo is great and very convincing. But using the app is a pain because of horrible defaults. First, the scroll area is much bigger than the document I'm looking at. I found myself fighting to re-center it. Second, the horizontal scroll directions are inverted. Scrolling left pans right. Scrolling right pans left. The app has myriad options, so perhaps these issues are easily fixed. But it's not a great first impression.