jgwhite33

Allows you to insert a listing of related Amazon products, on the single post page by using a custom field called amazon_search and inserting simple code in your template file. 
The listings are completely customizable according to parameters defined in the admin panel. If you include an Amazon Associate ID, you can even earn commission! Also allows you to share revenue with your authors on a multi-author blog. Whoever wrote the post gets credit in the listings. Creates a custom field on the author profile pages so they can input their campaign ID. Whoever wrote the post gets credit in the listing.
A few of the features:
<ul>
<li>Specify the search with a custom field in the post called amazon_search</li>
<li>Allows you to use the Amazon Associate Network</li>
<li>Allows multi-author blogs to share revenue, you can even specify the percentage to share</li>
<li>Can share revenue with the author of the post if you desire</li>
<li>Uses advanced search parameters</li>
<li>Display is easily customizable</li>
<li>Hides the affiliate link to Amazon</li>
</ul>

WP Amazon Ads

WP Amazon Ads - allows you to easily insert Amazon product listings into your WP posts, and earn commission from sales.

Automattic

Daniel Bachhuber

Gary Jones

Mohammad Jangda

Assign multiple bylines to posts, pages, and custom post types via a search-as-you-type input box. Co-authored posts appear on a co-author’s archive page and in their feed. Co-authors may edit the posts they are associated with, and co-authors who are contributors may only edit posts if they have not been published (as is core behavior).
Add writers as bylines without creating WordPress user accounts. Simply <a href="https://github.com/Automattic/Co-Authors-Plus/wiki/Creating-and-editing-guest-authors" rel="nofollow ugc">create a guest author profile</a> for the writer and assign the byline as you normally would.
On the frontend, use the <a href="https://github.com/Automattic/Co-Authors-Plus/wiki/Template-tags" rel="nofollow ugc">Co-Authors Plus template tags</a> to list co-authors anywhere you’d normally list the author.
For more detailed documentation refer to <a href="https://github.com/Automattic/Co-Authors-Plus/wiki" rel="nofollow ugc">the GitHub Wiki for this plugin</a>.
Co-Authors Plus is an almost complete rewrite of the <a href="https://wordpress.org/plugins/co-authors/" rel="ugc">Co-Authors</a> plugin originally developed by Weston Ruter (2007). The original plugin was inspired by the ‘<a href="https://txfx.net/2005/08/16/new-plugin-multiple-authors/" rel="nofollow ugc">Multiple Authors</a>‘ plugin by Mark Jaquith (2005).

Co-Authors Plus

No support at all , also it doesn't work with wpml

No Support - Not compatible with WPML

Not working

Works!

I rarely ever give 1 star reviews, but developers who take over a plugin - making a breaking change that took a while to resolve - and then refuse to follow standard practice by providing a changelog (despite requests) for future updates, cannot be trusted.

Avoid at all costs.

Cannot trust developers

Assign multiple bylines to posts, pages, and custom post types with a search-as-you-type input box.

WP Amazon Ads vs Co-Authors Plus