"The books have been scanned in high resolution and color so you can see the engraved illustrations, the beauty of the embossed covers, along with maps and even the texture of the paper the books were printed on."
Probably the same reason the UK license-fee-funded BBC initially supported iPlayer on Windows only - it's the most popular tablet platform (or so I believe). The Kindle\Android flavours are apparently on their way, let's give them a chance eh.
However there are totally open formats which you could use on all platforms...
I'm not sure the popularity of the iPad is actually as high as everyone thinks. I think that's the Apple marketing reality distortion field. I see WAY more Kindles and Android phones than I see iPhones and iPads on trains in and out of London where I live.
The iPad is by far the most popular tablet and still makes up over 50% of the market. The iPhone is a vary popular phone, but there are far more options for phones out there than tablets.
Define "competitor" and "popularity". It's all damn lies and statistics.
My old Windows tablet could be a competitor. Dell do a tablet Windows machine. Motorola do a hybrid device. Is an ebook reader a tablet? Is an iPod touch a tablet?
Perhaps people with iPads hammer web sites? Perhaps people without iPads don't? Perhaps some mobile browsers identify themselves as desktop ones?
There is no defined taxonomy to classify things in either.
Every time I read about the BL they're doing something inanely anti-web, though usually Microsoft-centric, like putting interesting audio online as .WMA files, or buiding things in silverlight that would have been as easilydone in javascript, or supporting OOXML for fast-track ISO standardisation.
I'd suggest two things are of value in this app: firstly, the the "format" of these particular editions, and, secondly, their curation as an app.
If you want to read "Excursions in Madeira and Porto Santo", by T. Edward Bowdich, Esq. (one of the books), then archive.org has an excellent copy, here:
However, you probably would never read such a book. You may, however, browse through the version included with the British Library app. The BL version is a very nice edition, with colour plates. More importantly, the BL version is presented as part of a collection of interesting old books, which means that a lot more people will be reading about Mr. Bowdich, Esq.'s adventures this weekend than would normally be doing so.
The presentation of the books is of general interest. By contrast, the actual text content of the book is of very specialised interest, and the (decontextualised) pictures not much less so.
The problem is that there are now a pile more mediums to deliver the message on depending on how much you can afford to pay out.
The information should be uniformly available to all, which I believe is the point of the British Library.
However, having been there a number of times, it's a pain in the arse to use the BL anyway and copying anything for reference (like you used to do down your local library) is virtually impossible now. So it's literally sit and copy the work out.
format is important in order to make sense of content.
I'm sure right now they have a huge database with lots of scanned images, and an app like this helps to make sense of it. If I'd have a big zip file containing all those books, it would be difficult to browse through them. They said they're planning to add support for other devices, so you may still get what you want one day.
Text files take away the writer's intent. "To Sherlock Holmes, she is always be the woman." That is a rare instance of Conan Doyle using italics. And he meant it.
Then you are certainly not the target audience.
"The books have been scanned in high resolution and color so you can see the engraved illustrations, the beauty of the embossed covers, along with maps and even the texture of the paper the books were printed on."
A better quip would involve PNG files.