csfeijo

ContentShare use the API features of Twitter and Facebook to possibility add this buttons on your blog. 
For more informations about this features see the API URLs of this Social Networks.

ContentShare

ContentShare add buttons to share on Twitter and Facebook (Share and Like) on home page of your blog and on each post.

andreyk

The WP Ya.Share plugin adds to your blog a set of buttons to save URLs of your pages/posts in popular social networks (twitter, facebook, livejournal, vkontakte etc.).
Добавляет блок ‘Поделиться’ (Ya.Share, разработанный в yandex) для сохранения ссылки просматриваемой страницы вашего блога в популярных ‘социальных сервисах’ (вконтакте, жж, твиттер и т. д.).
It uses the Yandex Ya.share API; I shaped it into wordpress plugin with some options only.
The following options are available:
<ul>
<li>locate “ya.share” block either in the content of a page/single post or in the sidebar (as a new widget);</li>
<li>select a list of preferable social networks;</li>
<li>button/link/icon for expanded social networks list, or nothing;</li>
<li>left, right or centered location;</li>
<li>above or under the content;</li>
<li>inscription language. 
Please feel free to contact me with your questions or suggestions.</li>
</ul>

WP Ya Share

Adds the Yandex 'Share in social networks' block into posts or widget to simplify saving URLs of your blog pages into social networks.

ContentShare vs WP Ya Share