Steve Grunwell

<a href="https://codex.wordpress.org/Excerpt" rel="nofollow ugc">WordPress post excerpts</a> can be a great way to hand-craft the summary of your content. Unfortunately, writing post excerpts isn’t as nice of an experience as what you find elsewhere in WordPress. Want to include links in your excerpts, or bold some text? Hopefully you know some HTML!
Advanced Post Excerpts is designed to change that, by giving your editors an easy, intuitive interface for writing great post excerpts.
For complete details and/or to contribute to ongoing development, please <a href="https://github.com/stevegrunwell/advanced-post-excerpt" rel="nofollow ugc">visit this project on GitHub</a>.

Advanced Post Excerpt

Replace the default Post Excerpt meta box with a superior editing experience.

Jonathan Brinley

The standard excerpt field will appear on pages, just as it does on posts.
Additionally, there is a new widget to display the excerpt of a selected page.
Created by <a href="http://flightless.us/" rel="nofollow ugc">Flightless</a>

Page Excerpts

The plugin is built for something very specific, and does it perfectly.

Simple but effective

Adds an excerpt field to pages, and provides a widget for displaying page excerpts

Advanced Post Excerpt vs Page Excerpts