E-book apps such as Kindle and iBooks provide excellent capabilities for reading long, continuous prose whereas custom apps offer superior mechanisms for presenting narratives that significantly incorporate a range of options, including animation, audio, images, and video as well as new forms of interacting with the book.

When an app serves our purpose most will accept its limitations. We’re seeing that most clearly with all the e-book reading apps. Some people hate iBooks simulated page turning with the faux borders of a print book. Others prefer the more basic approach of the Kindle app. For reading long-form narratives most of us who have embraced e-books tolerate the idiosyncrasies of the Kindle app or iBooks since accessibility and portability far outweigh any disconcerting aspects of reading on a screen.

And that’s the difference between print and digital, and largely now the difference between e-books as apps and as ePub: apps can offer much more than reading on a screen.

The highly acclaimed Our Choice, Push Pop Press’s production of Al Gore’s text, is a remarkable example of how book apps can engage readers in learning about climate change, even offering an animated primer on how electricity is generated for those of us who never quite grasped the origin of electrical currents, underscoring the capability of an animation to convey more meaning than a static image. The static image needs more elaboration whereas the animated image is instantly graspable.

John Gruber properly analyzes the differences between e-books as known via Kindle/iBooks apps and the type of e-book offered up for example by Push Pop Press:

Kindle and iBooks seem to have the goal of reproducing what is possible in paper books. Yes, iBooks supports embedded video and audio content, but it does so in a way that feels as though Apple pondered what it would be like if you could play video on a piece of paper. Push Pop’s concept strikes me as far more ambitious: What can we do with the idea of a “book” if we eliminate the limitations of ink and paper, rather than mimic them? E-books that aren’t merely rendered by software, but rather e-books that are software.

It’s easy to see why textbooks will transition to this format and why companies are working to develop educational apps. Textbooks are not at all about reading long-form prose but about absorbing modular content that is carefully constructed to facilitate learning.

While JavaScript-enabled interactivity will emerge for ePub-based e-books and, surely eventually, also for Kindle e-books, those e-books must still be fitted within the constraints of their parent app, e.g., iBooks and Kindle.

The Web browser itself is an app. Web apps already allow us to present content without embedding it inside the visual frame of a browser window. Expect a time when the frame around e-book readers will be removed, too. Over the next couple of years e-book reading apps undoubtedly will edge closer and closer to incorporating a broader set of browser-like capabilities — most importantly full support for HTML5, CSS3, and JavaScript — so that the design and layout of e-books no longer must exist in the crippled state dictated by today’s iBooks and Kindle apps. But in that case: are e-books of the future anything other than Web apps?