Stephanie Leary

Creates widgets that display excerpts from posts or pages in the sidebar. You may use ‘more’ links and/or link the widget title to the post or page. Requires <a href="http://blog.ftwr.co.uk/wordpress/page-excerpt/" rel="nofollow ugc">Page Excerpt</a> or <a href="http://www.laptoptips.ca/projects/wordpress-excerpt-editor/" rel="nofollow ugc">Excerpt Editor</a> for page excerpts. Supports <a href="http://robsnotebook.com/the-excerpt-reloaded/" rel="nofollow ugc">the_excerpt Reloaded</a> and <a href="http://sparepencil.com/code/advanced-excerpt/" rel="nofollow ugc">Advanced Excerpt</a>.
Now on <a href="https://github.com/sillybean/Post-and-Page-Excerpt-Widgets" rel="nofollow ugc">GitHub</a>.

Post and Page Excerpt Widgets

Creates widgets that display excerpts from posts or pages in the sidebar.

J0SiE

Created to help those people who don’t like to edit code in template files (or are too lazy to do that). 
Just activate the plugin and it will automatically show the_excerpts in your homepage, archives and search results. 
It tries to display your custom excerpt text and if it doesn’t find it it will show an automatically generated excerpt. 
You can also define excerpt length, custom read more link and attach a thumbnail.

Auto Excerpt everywhere

Thanks to author for creating this plugin. 
It's works out of box. And working fine at WordPress Version 4.6.1


Works out of the box on WP Version 4.6.1

The plugin automatically displays excerpts instead of full post contents in your blog. Custom excerpts and generated excerpts supported.

Post and Page Excerpt Widgets vs Auto Excerpt everywhere