The website of this extension could be improved by:
Making the link to the Github repo more visible since it's currently relegated to the bottom of the page. There are other extensions doing similar things and the fact that this one is open-source is a big plus since it must have access to all the (potentially sensitive) data on mail.google.com
Including the instructions which at the moment are only included in the README in Github
The website of this extension could be improved by: