in my case it was official S60 app for .mobi ebooks, the format that most people might now know as Kindle (the difference is, afaik, to this day one byte being

in my case it was official S60 app for .mobi ebooks, the format that most people might now know as Kindle (the difference is, afaik, to this day one byte being swapped). To make it funnier, the files were essentially a Palm resource container with simplified HTML, and I had a reader on pretty much everything from my small 320x320 screen of nokia e51, through le random windows mobile GPS, various android devices, PCs, etc. :)