ineffyble

Causality allows your cause, charity, or nonprofit to promote your campaign using Twibbon-style image overlays
Causality allows you to set up a series of image overlays. Supporters on your site can easily add an overlay to their profile 
picture on social networks, promoting your cause.
<h3>Adding Facebook integration</h3>
<ol>
<li>Go to the <a href="https://developers.facebook.com/apps" rel="nofollow ugc">Facebook Developers page</a> and choose “Add a new app“</li>
<li>The Display Name should be the name of your website or organisation – it will be shown to supporters when it asks for their authorisation.</li>
<li>Choose a category, this doesn’t matter too much.</li>
<li>Click Create App ID.</li>
<li>Click Get Started for Facebook Login.</li>
<li>Click Save Changes at the bottom right.</li>
<li>Click Settings at the top right. Enter your website’s domain under “App Domains” (e.g. amnesty.org.au)</li>
<li>Click Add Platform at the bottom of this page, and choose “Website”. Enter your website under Site URL (e.g. http://amnesty.org.au)</li>
<li>Copy the “Application ID” shown at the top left. Enter this into your Causality settings.</li>
<li>Click Save Changes.</li>
<li>Finally, click “App Review” at the top left, and toggle the “Make YourApp Public” box to be “Yes”.</li>
</ol>

Causality

Causality allows your cause, charity, or nonprofit to promote your campaign using Twibbon-style image overlays

utahta

This plugin inserts social share links at the top or bottom of each post. 
For theme developers, social share links can be added by PHP code or by using shortcode. Check documentation for this use-case.
This plugin documentation can be found <a href="https://github.com/utahta/WP-Social-Bookmarking-Light/wiki" rel="nofollow ugc">here</a>.
This is the list of used social sites:
<ul>
<li>Hatena</li>
<li>Facebook Like Button</li>
<li>Facebook Share Button</li>
<li>Facebook Send Button</li>
<li>Twitter</li>
<li>Tumblr</li>
<li>Google Bookmark</li>
<li>Google +1</li>
<li>Delicious</li>
<li>Digg</li>
<li>reddit</li>
<li>LinkedIn</li>
<li>Instapaper</li>
<li>StumbleUpon</li>
<li>mixi Check</li>
<li>mixi Like</li>
<li>GREE Social Feedback</li>
<li>atode (toread)</li>
<li>LINE</li>
<li>Pocket</li>
<li>Pinterest</li>
</ul>

WP Social Bookmarking Light

This plugin inserts social share links at the top or bottom of each post.

Causality vs WP Social Bookmarking Light