As with the StickIt! board, we made the entire StickIt! Small Buttons module design open-source. All of it: bitstreams, schematic, PCB layout, documentation — everything!
When you order a StickIt! Small Buttons module, all you get is the board. That's it. The StickIt! Small Buttons module doesn't need any software itself. And the manual is online. As for the fancy box, well, sorry about that. Think of it as "saving the environment".
The StickIt! Small Buttons module manual will tell you how to install your board, and it shows how the buttons are connected to the I/O pins. And there is a design example online that shows how to use it.