wellflat

This is a plugin which gives you a small card to show your GitHub user profile summary. You just have to put shortcode.
Features include: 
+ GitHub account name and avatar 
+ recently active repository 
+ frequently used language list sorted by repository’s stargazers count 
+ public repositories and gists count 
+ followers count 
+ total stargazers count
Notice: 
This plugin caches GitHub user profile data into the database (expires 4 hours).

WP GitHub Card

This plugin provides simple GitHub profile summary card.

Jason Stallings

Github Shortcode is a plugin that allows you to embed a GitHub repository in a page or post using a simple shortcode.
Usage:
[github repo=”octalmage/Github-Shortcode”]

Github Shortcode

Easily display GitHub Repositories in Pages/Posts.

WP GitHub Card vs Github Shortcode