Martin's fantasy novel "A Dance With Dragons" finished the book, and spent an average of 20 hours reading it, a relatively fast read for a 1, 040-page novel.

WSJ: Your E-Book Is Reading You

Find a book and start reading in seconds with our fast, free wireless delivery.

ENGADGET: Amazon's new Kindles now available in Canada, Paperwhite starting at CAD $139

"Part of what makes this compelling is not so much reading every tweet but just getting a real-time sense of how fast this is moving, " he said.

CNN: New app tracks Colorado wildfires