I'm busy preparing the next update to Paperless. It will release some time in the next month. When it comes out, you'll be able to delete the current version from iBooks and download the updated version. You won't have to buy it again. I'll post the update notes and details when it releases. There are new screencasts, new sections, the works.
Next week, however, I'm raising the price for new customers to $10 so if you haven't bought it already, now is the time.