Aren't Chrome extensions just zip packages that contain bunch of HTML and JavaScript? Couldn't you "easily" just see what is in it? Of course author can update the extension at anytime and the JS can be obfuscated.
In some countries making copies and modifications for personal use is completely legal.
But it is lagging a month behind due to Firefox webextensions. I want the code to be compatible with all three browsers so I am releasing it according to Firefox's webextensions. Also, nobody ever cared to check the code from past two years so I never bothered to update it on Github. The only 1 star in the source code is my own star ;) Will do it soon.
That said, feel free to view/modify the crx/zip file as mentioned in the other comments. Will be glad if you can make any comments or suggest improvements to the code. :)