Alex Sawallich

This plugins enables the famous Google +1-button in your wordpress-installation. The button is shown beneath 
your posts/pages. With this button you can share the permalink to your post/page in your Google+ profile.
You’ve got the possibility to change the look of the button in the same manner, that you can do by using the 
configurator that Google provides: see <a href="http://www.google.com/webmasters/+1/button/" rel="nofollow ugc">Google plus one</a>.

Google+ One Button

Provides a +1 button from Google+ beneath each post/page.

the5kyliner

Include secure share-buttons from the three biggest social-media-platforms: facebook, twitter and google+. The buttons don’t include any scripts, so no data is transmitted unless the user decides to click the button and actually share the content.

TsBig3 Secure Share-Buttons

Include secure share-buttons from the three biggest social-media-platforms: facebook, twitter and google+.

Google+ One Button vs TsBig3 Secure Share-Buttons