As boring as that sentence sounds I think it is worth a second look. Rather than charging a subscription, like The British Library, or charging for individual titles (like most every ebookstore),is selling collections focused on specific topics.
The app in question is BiblioBoard, and it's based in part on the the work that BiblioLabs put into developing a similar app for The British Library. And in what I'm sure is not a coincidence, a lot of the content also appears to be drawn from TBL. It comes with 3 free collections and you can buy more collections for $16 each.
You can find the app in iTunes, and later this year the content should also be available online in most web browsers.
BiblioBoard offers more than 70 niche collections with titles like American Slave Narratives: A Historical Collection ,Fairy Tales: Favorite Tales From Around the Globe, The Olympic Games: A Historical Collection, and Myths and Legends: Stories from Around the World. The 3 free titles are focused on castles, railroading, and adventures on the high seas. The content looks to be scanned PDF, not any true ebook format,and it can be downloaded to your iPad (this is important to me so I did check). The app also offers the ability to share excerpts via email, Facebook and Twitter.
I used to be a hobbyist historian, and when you combine that with what I do for a living I'm sure you can understand why I am interested in this app. But what really caught my eye was the content being sold as a set. BiblioLabs is pitching it as "an entire curated universe of historical artifacts for the price of a single paperback book", and once you get past the exaggeration, there is some value to the idea.
And it's not one I've seen before. I can only recall seeing individual titles sold, like the consumer retail model, or access sold via a subscription, similar to the academic library model, so this hybrid approach is something new. Of course, BiblioLabs is selling collections of content they don't own, so my enthusiasm is tempered by their chutzpah.