Jesse Overright

Add Facebook and Twitter sharing for your blog posts and pages! Sharing your blog posts with Social Media Sharing automatically provides important details like featured images, title, and description to your blog so pages and posts look fantastic on Facebook or Twitter. Social Media Sharing adds Facebook Open Graph metadata and Twitter Card support to every page on your site, support for default descriptions or photos, and uses your featured images as thumbnails on social media.
Note: Twitter Card support requires approval from twitter. You can request approval at the <a href="https://dev.twitter.com/docs/cards/validation/validator" rel="nofollow ugc">twitter card validator</a>.

Social Media Sharing

Automatically add Facebook Open Graph and Twitter Card support to your WordPress website.

Rob Scott

Easy to use plugin that adds custom fields to posts to easily add Twitter Card metadata to your posts. This plugin requires Advanced Custom Fields by Elliot Condon.
<h3>Compatibility</h3>
This add-on will work with: 
1. Advanced Custom Fields version 4 and up 
2. WordPress version 3.8 and up

Eazy Twitter Cards For Posts

Easy to use plugin that adds custom fields to posts to add Twitter Card metadata to posts.

Social Media Sharing vs Eazy Twitter Cards For Posts