Fabio M. Giacomini

This plugin adds a new field in every post, where you can write a text that will be inserted in the related meta tag, located in the head section.
The main options page of the plugin, provides you with a default text area, where you can insert a default description that will appear in case the field in post page is empty.

Single Post Meta Description

The easiest way to add in every post page a different meta description tag, located in html head.

Dirigible Studio

Tired of bloated SEO plugins?
Us too. That’s why we built Dirigible SEO. We’re search engine optimization experts who use professional keyword research and tracking tools to optimize and refine our content outside of WordPress. 
We don’t need a complex plugin to help us accomplish our SEO goals—we simply needed a way to edit our title tags and meta descriptions within a WordPress page or post.
Dirigible SEO uses the power of <a href="https://www.advancedcustomfields.com" rel="nofollow ugc">Advanced Custom Fields</a> to set up everything you need to manage your SEO.
See it in action https://www.youtube.com/watch?v=Dd7ZeIrZMC0&feature=youtu.be

Dirigible SEO

Free, fast and easy search engine optimization for web developers & SEO pros. Edit titles and meta tags quickly and easily. All killer, no filler.

Single Post Meta Description vs Dirigible SEO