Kodetop

This plugin allow insert Tweet Button on your blog or site. The button can be customized in the settings page. Tweet Button can be positioned a the top, bottom of content. You can use text shortcut <code></code> and PHP function <code>wp_tweetbutton();</code> for manual insert.
Features
<ul>
<li>Easy install</li>
<li>Panel for easy configuration</li>
<li>Config Button Style</li>
<li>Config Language of Button</li>
<li>Config Your Twitter Account</li>
<li>Config Related Account</li>
<li>Config Tweet text</li>
<li>Config display locations (entries, pages, home page)</li>
<li>Config position in content (before, after, none)</li>
<li>Text shorcut: <code></code></li>
<li>PHP Function: <code>wp_tweetbutton();</code></li>
</ul>
Manual usage of WP-TweetButton:
For include into post content use: <code></code>
For include in your template use: <code><?php wp_twitterbutton(); ?></code>
For more information visit <a href="http://blog.unijimpe.net/wp-tweetbutton/" title="plugin website" rel="nofollow ugc">plugin website</a>

WP-TweetButton Plus

This plugin allow insert Tweet Button on your blog or site.

Jason Yingling

This plugin allows you to easily create pull quotes in your posts by adding a button to the post editor. As an added bonus, pull quotes can be easily shared to Twitter by the end user by clicking the Twitter icon.
You’ve got 3 options for pull quotes, full-width, right-aligned, or left-aligned. Easy Pull Quotes will take on the styles and font sizes from your theme. Plus be on the lookout for customizer options coming soon!

Easy Pull Quotes

Easily add tweetable pull quotes to your posts.

WP-TweetButton Plus vs Easy Pull Quotes