Compared to other book database apps that charge nominal purchase fees, this app really evokes the you get what you pay for concept. Aside from the random crashing during the book input process, the features of this make you really feel that this is a stand-alone app, similar to a spreadsheet. I prefer apps that are more interactive with other readers, libraries, and the developer. I found that Book Crawler, provides these features and continual support and updates that increase the feature line up.
Update: Book Crawler now offers in-app purchases that allow for more functionality out of the gate than this app. Try before you buy is the best way though!