endsoftdesign

Inserts Google + 1 Button in your site from the Dashboard. No code necessary!
You do not need to edit the theme. New GooglePlusOne is the easy way to insert the Google+1 in your site without have programming knowledges.
Features
Google + 1 will be added automatically in all your posts and pages. You can customize the place where the button will appear, by changing its position or by choosing another HTML element which will contain it.
Also, you can choose to have a single Google + 1 button in your site’s header.
<h3>Markdown</h3>
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New GooglePlusOne

Inserts Google + 1 Button in your site from the Dashboard. No code necessary!

SISCOM WEB DESIGN

This is a simple plugin without any hassles, it automatically adds the Google Plus One Button to your WordPress posts and pages. 
There is no admin for this plugin since everything is done automatically, just upload the plugin , activate it and it will add the necessary code for the Google +1 Button to appear on every post and page. 
The Button will be located at the Top-Right Corner Inline with your posts.
Features:
<ul>
<li>Automatically included on Posts</li>
<li>Automatically included on Pages</li>
<li>Button location is at the Top-Right Corner Inline With the Text</li>
<li>Simple enough, Does not slow down your site, Does not mess up other plugins</li>
</ul>

WP PlusOne This

The WP PlusOne This plugin, automatically adds the Google Plus One ( +1 ) Button to your WordPress posts and pages.

New GooglePlusOne vs WP PlusOne This