Gianluigi Filippelli

<a href="https://wordpress.org/plugins/co-authors-plus/" rel="ugc">Co-Authors Plus</a> is one of the most useful plugin for multiple authors blogs. This plugin add a widget to add users’ avatars to post also for guest authors and for posts with multiple authors. 
You can also add avatars with a shordcode [blog-post-coauthors]. 
The plugin add also a slider in order to show user’s profile. If you want change the style, you can modify blog-spoiler.css file in the plugin folder.

Co-Authors Widget

The plugin add a widget and a shortcode in order to show authors of an article. It is compatible with Co-Authors Plus.

Frank Neumann-Staude

Ulf Schönefeld

polyres

This plugin/add-on requires the plugins FacetWP and Co-Authors Plus (WordPress plugin repository)!
This free plugin/add-on integrates FacetWP with Co-Authors Plus, allowing you to use Co-Author Plus custom fields for front-end search and filtering in a facet. 
With the help of Extend Co-Authors Plus for FacetWP, you can create a lable and choose the data source “co-authors” for your page or post.

Co-Authors Widget vs Extend Co-Authors Plus for FacetWP