It was an interest in leveraging their backgrounds--hers in social media and his in social gaming--that inspired Palo Alto-based tech entrepreneurs Andrew Goldman and Rachel Thomas to try and come up with a way to make reading a truly interactive experience. The result is Subtext, a free iPad app that, as of today, is available in the Books section of the apps store. The app goes live with 18 titles and allows users to read books with notes and feedback provided from authors, as well as people in their online social circles.

Goldman and Thomas said while their venture is entirely funded by venture capital at this point, there are myriad ways to monetize the app. Users who download the app can peruse a sampling of books--among the 18 launch titles are George R.R. Martin's Game of Thrones and Lisa See's Snow Flower and the Secret Fan--already outfitted with some extra content, mostly notes (as well as outside videos and Web links) provided by the authors, or others close to the work. To integrate new titles into the app, users can pull from their Google Bookshelf. (Because Amazon and Apple's systems are closed, Kindle and iBookstore libraries are not compatible.)

Once titles are uploaded into the app, users can connect with friends via Facebook to jointly read titles, sharing comments and posting feedback. One key for the app though, as Thomas explained, was ensuring users could set the level of interactivity. Subtext therefore has settings through which readers can control how much, or how little, feedback they see. Using the settings, a reader can see notes from only the author, only their friends, or everyone using Subtext. The settings can also be used to filter when a reader sees notes, so someeone could read comments throughout, as they go, or wait and see comments once they have finished a book.

The Subtext founders have been talking with all of the big six publishers, as well as smaller players, and their hope is to encourage as many authors as possible to create their own enriched titles. The app also is open to other forms of content, going live with a sample of Holly Finn's Byliner original "The Baby Chase," an article about the author's struggle to get pregnant, in her 40s, through IVF. For Subtext, Finn updated the story with news about how things have been going, after the Byliner piece originally ran.

With potential in academic circles, as well as the trade, Subtext could certainly be an ideal tool for sharing notes in a classroom setting, as well as a book club. Although there are not currently tools to allow users to create groups within groups for reading titles, Thomas said the thinking is that this functionality will be forthcoming, and that soon there will be the ability to have things like Google Circles, in the app. Also, though the app is currently geared for adult titles that are text-driven, the ability to feature graphic novels and children's picture books, may be a feature down the road.