Python, NodeJS, Web-Ext.
npm install -g web-ext
Run addin in Firefox using:
web-ext run
The above will run with a temporary Firefox profile.
To use your own profile and also persist changes to that profile:
web-ext run --keep-profile-changes --firefox-profile=<path to your profile>
You can easily find the path to your Firefox profile by going Firefox's hamburger menu > Help > Troubleshooting information.
https://addons.mozilla.org/en-US/firefox/addon/newtabtodo/
Contributions are very welcome!
Check Issues for things that need doing.
Use plain JavaScript, no libraries.