Brian Onorio, O3

This plugin makes syndicating your content to social networks easy. While other plugins have 100s of available networks you can connect to, this plugin makes it easy to post share buttons for the 4 big networks: Facebook, Twitter, Google+, and LinkedIn. Who uses Ying Yang and Bamalamadingdong anyway? Once activated, you will see a series of social plugins at the bottom of each post allowing your site visitors to quickly and easily post the content on your site to their profiles on these networks.
The plugin has a robust options panel allowing you to pick and choose which networks to support. You can also customize the Facebook and Twitter plugins in the exact same was as you would be able to if you were pulling the plugin code directly from the supporting website.
Default Options include:
<ul>
<li>Choice of any or all of the following networks: Twitter, Facebook, Google+, and LinkedIn</li>
<li>Customization of tweet content allowing you to use to use the page title or to customize it</li>
<li>Add a Twitter user to the tweets</li>
<li>Add a hashtag to tweets</li>
<li>Include or exclude the Facebook Send button</li>
<li>Choice between Facebook verb to use (Like or Recommend)</li>
<li>Option to include default styles or leaving the styling up to you</li>
<li>Place the Social Plugins above the Post Content, below the Post Content, above and below the Post Content, or place them manually</li>
<li>Restrict the Social Plugins to just the posts, pages, or any other registered custom post type</li>
</ul>
For more information on this plugin and support for this plugin, visit <a href="http://www.weareo3.com/plugins/o3-social-share/" rel="nofollow ugc">O3 Social Share on O3</a>.
Note: The Facebook “Send” button, when activated, sometimes disappears on some browsers after a momentary display. This seems to be connected to a Facebook bug documented here: <a href="https://developers.facebook.com/bugs/299191993489218?browse=search_4f9eab716e1110276007093" rel="nofollow ugc">Facebook</a>.
<h3>Usage</h3>
Simply activate the plugin and you’re all set.

O3 Social Share

This plugin will add social share icons for the 4 major networks to the bottom of WordPress posts.

Brian Messenlehner

Display a Google+ Direct Connect Badge on your site via widget or shortcode, allow your members to login/register via their Google+ account or sync your Google+ stream with your blog posts or BuddyPress activity via the Google+ API.
WordPress Google+ Connect allow your website members the ability to register and/or log in via their Google+ account utilizing the Google+ API. Set up a Google Plus Application and store the API credentials in the WordPress backend, when a user clicks on the “Login with Google+” button that gets added to the WP log in screen or anywhere via a short code and authenticates their Google Plus account a WordPress account will be created with their G+ information and they will automatically be logged in. Any existing WordPress users can also log in via Google+ and link their two accounts.
If BuddyPress is enabled a Google+ login button will appear on the sidebar login and the registration page. Google+ profile photos will also be imported in as BuddyPress avatars. Members can stream their Google+ activity into their BuddyPress activity if they choose via the Google+ options screen under the logged in BuddyPress members profile settings page. A cron job runs every 30 minutes to import any new Google plus activity from connected users.
Configure Google+ Direct Connect and help visitors find your Google+ page and add it to their circles from directly within a Google Search.
Configure your Google+ Badge and allow visitors to directly connect with and promote your brand on Google+. Visitors can also add your Google+ page to their circles directly from your website. Badges are easy to configure and can be placed on your website via a short code or a widget.

WP Google Plus Connect

Add Google+ Direct Connect Badge & allow your WordPress/BuddyPress users to register or login via their Google+ account & import their stream  …

O3 Social Share vs WP Google Plus Connect