LinkeTheme is an eye-catching cleaner theme extension for LinkedIn, it's open source and available for Firefox, Chrome and Opera.

Stylish-hub is an extension that brings new GitHub features and experience like: YouTube or Vimeo videos, Codepen, CodeSandbox, Repl.it and Slideshare support on markdown files. Ability to show/hide specific content for those who uses the extension and more.

Aura Theme is a beautiful dark theme including variants focused on long-term work without causing any discomfort to the eyes.