Social e-reading platform BookShout! has inked a deal with HarperCollins, Macmillan, Wiley and Content Group, adding to the 250-plus publishers whose e-books are now available via the app. With the addition of five of the "Big Six" publishers, BookShout! now has more digital books available than Apple did for the launch of its iBooks store.

Capitalizing on the growing digital market, Dallas-based Rethink Books launched BookShout! in April on the iPhone and iPad, and it is now available on iOS, Android and the Internet. Touted as "a revolutionary new reading platform," BookShout! enables users to engage and interact with each other while reading digital books—allowing friends to read books together, whether nearby or far apart.

"Some of the world's largest publishers are innovating with us, which is beneficial to the entire digital publishing ecosystem," said Jason Illian, CEO and founder of BookShout!, developed during the past two years for the Christian market.

Every major Christian publisher participated in the BookShout! launch with a number of free e-books. Approximately 10,000 titles are now available for purchase through the BookShout! store from publishers such as Zondervan and Tyndale House Publishers.

BookShout! also announced recently at the Frankfurt Book Fair "a revolutionary new disruptive technology" that enables users to make e-book purchases from any source—starting with Amazon's Kindle and Barnes & Noble's Nook—and use them on the social e-reading platform at no additional cost.

Consumers previously had to read their e-book on the e-reader for which it was purchased. Illian developed the technology that "enables readers to create a universal bookshelf and have new tools to help with discoverability and sharing," company officials said.

"In essence, we are tearing down the walls the large e-book retailers have established, and are no longer allowing them to build consumer-unfriendly fiefdoms," Illian said. "We are giving the consumers the freedom to access their book purchases when and where they want them, which is the whole point of digital publishing."

In other news from Frankfurt, Book Industry Study Group and representatives from 16 countries announced the formation of a new global standard to categorize and classify book content by subject called Thema.

The new standard is flexible, allowing "each market to retain its unique cultural voice while still presenting a unified hierarchy that rationalizes book categorization," organizers said. "The goal of Thema is to reduce confusion about subject codes for both upstream and downstream trading partners in order to facilitate the sale of more books."