I'm writing this review as I'm going through this on Steam, and will serve as a log of my experience with using it.
Once Final Hours of Titanfall (this is the name it will be listed under when you look for it in your Steam library) is "downloaded", running the application will launch an Adobe Air installer - this will install Adobe Air onto your computer if you don't already have it, as well as the actual "book".
First attempt at running ended up causing an error and the install failed. After unckecking "Add desktop icon" and "start after install is finished", it installed successfully after the second attempt.
From there I went back to my library to run the program, a prompt from Adobe Air showed up, asking if I wanted to uninstall or run, so I chose to run the program.
From there going through the application is easy and simple - use the arrow keys or mouse to navigate, and close the window like you would any other window.
Obviously the people that would be interested in this would be those that would like to know more behind the history of Respawn and Titanfall, as well as getting a glimpse of some of what goes into making these kind of games. If you're into that stuff, I'd recommend it.
HOWEVER, if you're running a Windows 8 computer, I'd recommend using Microsoft's Bing Rewards program to get a $3 gift card for the Windows Store, and purchase it through there without having to worry about having to wait through the install process of Adobe Air.