Darker Medium applies a customizable dark theme to *all* medium formatted stories. You can customize the header background, main accent color, highlight color and link styles separately from the option menu. No matter the domain, if a site is using Medium, it will get a dark theme; that is the main advantage over Stylus and Stylish.
Sblack is a little free Mac app that applies a Dark Theme to Slack for Mac to make it easier on your eyes. Just drag and drop and you're done!
Darkdocs adds a dark mode to your Google Docs writing experience.
Enjoy Instagram web in the new night blue colors and protect your eyes
This Chrome™ extension changes page colors, brightness and contrast to increase readability and brings dark night mode to the world wide web.
✔ Inverts brightness instead of colors
✔ Improves readability
✔ Blue filter replaces blue light with red
✔ Activation and deactivation schedule
✔ User can add new themes
✔ Free forever
Night Mode for Desktop allows you to save your eyes when using Twitter when it's dark out. Twitter introduced Night Mode to mobile last year and now they are finally bringing it to desktop.
Dark Reader for Safari makes all websites dark, relaxing your eyes. Perfectly suits to macOS Mojave dark mode.
HappyOwl is a FREE chrome extension to turn night mode on for medium.com
Turn Quora UI into dark mode for ease on the eyes and improved readability.