You can download a version of Sentient Sketchbook below. This version matches that documented in the 2013 paper at the Foundations of Digital Games Conference (see References for more details), although a more elaborate visualization for final maps is included.
In order to use the tool, download the zip file and unzip it. Inside the SentientSketchbook2014 folder which will be created, you will find a SentientSketchbook.jar file, along with folders for the libraries used. Running the jar file requires that you have Java Runtime Environment installed, which usually comes pre-installed with most operating systems. When you use Sentient Sketchbook, a logs folder will be created, where all of your design sessions are stored (each in a folder containing its session number). The exported final levels are also stored in that session's log folder.