You can allow users to "Google +" a specific item or product by adding the "social button" option in your layout builder.
EVERY page that has an item/product list frame has a layout builder. First you should determine where you want to display your "Google +" button. (whether its on the Item/Product page or Item/Product details page.
When you are in your layout builder you may want to make some columns for the social buttons to keep them together and neat.
In this example I have added 4 columns. (3 for my buttons and 1 to use up the extra space so the buttons are together)
In the Second column I am going to put the "Google +" button. to do this you need to go to the column or space you wish to add it and then click the "+" button and select "social button".
see screenshot:
Once you click on the "Social Button" option you will have a screen pop up with options for what type of social button you wish to display.
see screenshot:
In this example I wish to add the "Google +" button. You will see an example of how it will look as you change options in the bottom window.
Click apply.
Then be sure to Save your layout. and preview.