ablancodev

Synchronizes wordpress users with MailChimp. Select MailChimp list, group and subgroup (subscribers organized in a subgroup or according to your role), and automatically new users are added to this mailchimp group. 
Add, update and delete synchronized users.
Official site: <a href="http://eggemplo.com/plugins/users2mailchimp/" rel="nofollow ugc">eggemplo</a>

Users2MailChimp

Synchronizes wordpress users with MailChimp email marketing service.

evokelektrique

Replicant
A plugin that replicates and synchronize content in your WordPress websites.
<h3>Features</h3>
<ul>
<li>Sync WordPress posts, including (Create, Update, Delete) across all trusted nodes</li>
<li>Sync WordPress pages, including (Create, Update, Delete) across all trusted nodes</li>
<li>(SOON) Sync WordPress comments</li>
<li>(SOON) Sync WordPress users</li>
<li>(SOON) Sync WooCommerce products</li>
</ul>
<blockquote>
Note that currently the depth limit of nodes could be only 1 and maybe in futrue updates we will increase the limit.
</blockquote>
<h3>Example use case</h3>
<ul>
<li>
For example if you need to create chained websites, The problem arise when you need to copy countless content in multiple websites, Replicant makes this job simple and easy for you.
</li>
<li>
You want to have a backup of your posts or pages with their metadata included, Replicant is a good choice for you.
</li>
</ul>

Replicant

A plugin that replicates and synchronize content in your WordPress websites.

Users2MailChimp vs Replicant