Does anyone know any good module for adding stickers to the products? I need it a lot
Here is the module you need - On Sale + Product Labels by Aheadworks.
All labels appear according to you rules and with your design. So you can implement a rule to any number of products.
You can try our Magento Product Label extension to add labels on product images. You can add text and the image labels on products. The admin can also add multiple labels on each product and set their display priority.
It's awesome you can add stickers or labels to highlight discounts for your products like you need. Refer below link for more details