I now have the Columbia University Press book I'm reading thru Netgalley on the iPad, the kindle and on the Macbook. Maybe I'll figure out a way to go to a particular location in Bluefire and use it for tracking Sources; it would certainly be more convenient than using the laptop for that.
ETA: Wow. I had to look at the help screen to figure out how to get to navigation from within the book: tap the _center_ of the page. It works really well and is very clear once you know that little detail, but I was trying all the edges because that's what I'm used to on the kindle. Live and learn.