neon

If you write something like “@nick, how are you?” this plugin will search for @nick’s url in the comment list of the current post and will convert his/her name to a link.

Twitter style links

This plugin allows you to add Twitter style links to comments.

linkbld

Plugin adds a check box to the Write Post editor. When this box is checked, plugin automatically tweets each new blog post with a link of course. 
Maximum advantage of simplicity. In the WP admin interface, set necessary keys. 
Automatic tweet an older articles with one click. 
If a post is longer than 140 characters, it will be cut down. For most of this area did not take a link to your site, supports plug and Shorten Service bit.ly 
Auto twitter followers stay informed plugin put your social media to autopilot.

Auto twitter followers stay informed

Automatically tweets each new blog post directly to twitter. Get Top backlinks, inform your followers in real time, all on autopilot.

Twitter style links vs Auto twitter followers stay informed