PeepSo
A full-featured social networking plugin for creating communities with WordPress.
Popups Premium
The easiest way to create a WordPress Popup
WordPress to Buffer Pro
Automatically send content from WordPress to your Buffer account for scheduled publishing to Facebook, Twitter, Google+, LinkedIn and…
Revive Old Posts Pro
Revive Old Posts helps you automate sharing old (and new) posts on Facebook, Twitter, LinkedIn, Tumblr and Xing.
Yoast SEO
Extra features, more support!