YITH WooCommerce Product Add-Ons allows you to configure additional options that can be added to product in your shop. For each action, it’s possible to choose a name, an image and a price, which will add up to the basic ones the product has.
You will only have to activate both plugins in order to make them work together. After that you can either add your product add-ons via the product edit page, or via the add-ons menu.
The combined use of YITH WooCommerce Product Add-Ons and YITH WooCommerce Product Bundles allows adding custom product options also to “Bundle” products.
For more information on how to set up add-on options, check the complete documentation here.