MikesPickz

The MP Share Center allows you to easily add share buttons to your posts and pages.
The plugin will add Facebook Like, Twitter Tweet, LinkedIn Share, Pinterest Pin, Pocket and email buttons or boxes, above or below the front page/post/page/archive/search pages if you enable these options.
For the Facebook Like Button, the plugin will automatically take the first image from a post and use that as the thumbnail.
This plugin loads Javascript in the footer, which improves page load (by allowing content to appear first) and therefore benefits SEO and search engine ranking.
You can display the MP Share Center on any page type with the use of the shortcode <code>[mp_share_center]</code>. The shortcode defaults to use the buttons format. To choose the boxes format, simply add the <code>type='boxes'</code> parameter, ie: <code>[mp_share_center type='boxes']</code>. If you want to insert the call to action via the shortcode, use <code>[mp_share_center type='cta']</code>. Which social networks the shortcode displays is controlled on the MP Share Center Settings page.

MP Share Center

The MP Share Center allows you to easily add share buttons to your posts and pages.

bozdoz

Let your visitors share a quote from your pages with Quote Tweet!
When a visitor selects text from one of your pages, a prompt appears for them to share the quote, with the current page URL, to Twitter.
Check out the source code on <a href="https://github.com/bozdoz/wp-plugin-quote-tweet" rel="nofollow ugc">GitHub</a>!

Quote Tweet

A plugin that shows a link when a user selects text on your WordPress site to quote that text, with the current URL, in a tweet.

MP Share Center vs Quote Tweet