NOTE (2018-02-28): Frederic Da Vitoria confirms that the export script also works if you have the Kobo application for Windows PC. In this case the database file is called Kobo.sqlite and is located ...
$ git clone git@github.com:asib/polar-flow-export.git $ cd polar-flow-export $ python -m virtualenv env $ . env/bin/activate (env)$ pip install -r requirements.txt ...