It is installed by default in the home directory. But then it can be moved anywhere and launched by executing /pysheng/bin/pysheng-gui. Path to that could be added into a launcher (desktop file) put in ~/.local/share/applications
git clone https://github.com/tokland/pysheng cd pysheng sudo python setup.py install
Each page is downloaded as a separate png file. To create one pdf book out of it, see HERE.