This plugin 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.
If you have a bit of HTML knowledge it would help.
I find some difficulty in installing this plugin. I have activated the plugin with default settings, yet no plus one displayed?
The +1 is only shown if activated from wp-admin plugin configuration page found under the Appearance menu.