Here is a list of jekyll plugins that can be used on Github using the static site generator Jekyll:

• github-pages-health-check: Checks site for common DNS issues
• jekyll-avatar: Helps render github avatars
• jekyll-coffeescript: Write Coffescript instead of Javascript!
• jekyll-commonmark-ghpages: Use commonmark!
• jekyll-default-layout: Set the default layout for posts and pages
• jekyll-feed: Generate an atom feed
• jekyll-gist: Liquid template for including gists
• jekyll-github-metadata: Access repository metadata
• jekyll-mentions: Github @mention support
• jekyll-optional-front-matter: Front matter is now optional
• jekyll-paginate: Default (deprecated) pagination engine for jekyll
• jekyll-readme-index: Render readme as site index
• jekyll-redirect-from: Redirect to a page from multiple URLs
• jekyll-relative-links: Convert md links to html links; useful for when you want to have both your repository link to markdown files, and your site link to html
• jekyll-remote-theme: Use some other theme other than the default ones
• jekyll-sass-converter: Sass instead of CSS!
• jekyll-seo-tag: Add SEO tags (Facebook, Twitter, etc.) to your pages
• jekyll-sitemap: Add sitemaps.org compliant sitemap
• jekyll-titles-from-headings: If a site doesn't have title front matter, auto-adds it from the first heading
• jemoji: Emoji for jekyll
• kramdown: Write in Kramdown
• liquid: Use the liquid engine for templating (default)
• rouge: Use rouge for syntax highlighting

Source: github pages-gem