Pocket hardbacks in miniature are not a new thing, I have several from the 1960s which comfortablly go into pant pockets.

But I remember a fad from 3-4 years ago, for enabling one handed reading, called flipback binding, ie paperbacks with printing that goes in the long direction instead of the short direction on the page, so you hold it with one hand, read top to bottom, flip next page again go top to bottom, rinse and repeat.In theory a great idea, but I haven't actually tried one.