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 the Java Runtime Environment installed, which usually comes pre-installed with most operating systems. 

When you use Sentient Sketchbbok, 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. 

Browse through the tutorial within the tool if you're stuck.