A userscript that automatically logins to the sites you have configured under about:blank#auto_login
You can fetch the latest release from the releases tab. Installation requires GreaseMonkey and opening the *.user.js file in your browser.
Install node (for dealing with JavaScript)
apt install node
Install package dependencies
node install
Build es6 to es5
gulp
The compiled JavaScript can then be found under out/main.user.js
To automatically build upon file changes in the src directory run
gulp watch