Just a quick heads-up: Firefox Quantum is now available for download. The new version of the popular browser is twice as fast as Firefox from 6 months ago, comes with a sleek UI, allows you to customize the toolbar, includes Pocket recommendation of what sites to browse on every new tab, and takes up less memory than Google Chrome.
Night Mode and other features are available as free Firefox add-ons. For more info check out this Mozilla blog post.