fullo

The Ribbon Manager plugin give the ability to add a side ribbon on the blog without touching the template file or the css. 
Please note that the plugin needs a theme with <code>wp_head();</code> and <code>wp_footer();</code> enabled.
<h3>Arbitrary section</h3>

FCC Ribbon Manager

The Ribbon Manager plugin give the ability to add a side ribbon on the blog without touching the template file or the css.

starblank

Add NEW, SALE and OUT OF STOCK stickers to your woocommerce products, with custom text, colors and image. Easy and fully customizable!
Installation
Simply upload the .zip file into wordpress, then activate the plugin. A new menu called Stickers will appear on left bar
How to use
In Stickers menu you will see three tabs, one for new product stickers, on sale products and out of stock products. 
Each type of sticker have their own configuration. Each tab allows you to:
-Use a text ribbon, a custom image of both 
-Change text of the ribbon 
-Change color of the text and color of the ribbon 
-Select ribbon position 
-Alternatively you can use a custom image instead of a ribbon 
-Use custom css text boxes for fully aspect customization
Have fun!

Custom Product Stickers for Woocommerce

Add NEW, SALE and OUT OF STOCK stickers to your woocommerce products, with custom text, colors and image. Easy and fully customizable! Installation …

FCC Ribbon Manager vs Custom Product Stickers for Woocommerce