Miled

WordPress Social Login allow your website readers and customers to register on using their existing social accounts IDs, eliminating the need to fill out registration forms and remember usernames and passwords.
WordPress Social Login also allow you to import users contact list from Google Gmail, Facebook, Windows Live and LinkedIn.
WordPress Social Login gives you absolute control over users access to your website and comes a list of rules and restrictions for you to setup.
Easy to customize and integrate 
Wordpress Social Login come with a simple but flexible and fully customizable authentication widget. And if you are a developer or designer then you can customize it to your heart’s content.
Wide variety of providers 
Depending on the audience you’re targeting, you can choose from a wide variety of providers and services including: Social networks, Microblogging platforms, Professional networks, Media, Photo sharing, Programmers and Gamers networks.
Currently supported providers 
Facebook, Google, Twitter, Windows Live, Yahoo!, LinkedIn, Reddit, Disqus, Tumblr, Stackoverflow, GitHub, Dribbble, Instagram, 500px, Foursquare, Steam, Twitch.tv, Mixi, Vkontakte, Mail.ru, Yandex, Odnoklassniki, Goodreads, Skyrock, Last.fm, AOL and PixelPin.
Free, unlimited and white-label 
Wordpress Social Login is open-source and completely free. The source code is publicly available on <a href="https://github.com/hybridauth/WordPress-Social-Login" rel="nofollow ugc">GitHub</a> for anyone to help and contribute. You are free to use a WordPress Social Login in commercial projects as long as the copyright header is left intact.
Big thanks to everyone who have contributed to WordPress Social Login by submitting Patches, Ideas, Reviews and by Helping in the support forum.

WordPress Social Login

WordPress Social Login allow your visitors to comment and login with social networks such as Twitter, Facebook, Google, Yahoo and more.

LinksAlpha

** Track growth of your blog on social networks such as Facebook, Bitly, Google Buzz 
* View most popular posts by days/weeks/months 
* View graph of how your posts perform on different days 
* Real-time Analytics 
* Track Top Content Creators 
* Track Top Social Referrers
** Check out our other plugins that you will find extremely useful:** 
* Network Publisher: auto publish your blog posts to Twitter, Facebook, LinkedIn, Yahoo, Yammer, Identi.ca, and MySpace. https://wordpress.org/extend/plugins/network-publisher/ 
* 1-Click Retweet/Share/Like: Adds Facebook Like, Facebook Share, Twitter, LinkedIn Share buttons to your website. https://wordpress.org/extend/plugins/1-click-retweetsharelike/
Misc 
* For getting support, sharing feedback, giving suggestions: support@linksalpha.com 
* Note: We encourage you to download the latest version of the plugin as soon as it becomes available – as it may have additional extremely useful features for your blog.

Social Stats

** Track growth of your blog on social networks such as Facebook, Bitly, Google Buzz

WordPress Social Login vs Social Stats