Google Merchant Feed XMLs for WooCommerce, Easy Digital Downloads, and Custom Product Pages.
E-Commerce Plugin Not Required:
A supported e-commerce plugin, like WooCommerce or Easy Digital Downloads, is suggested but not required — the WPSSO Google Merchant Feed XML add-on also retrieves custom product information entered in the Document SSO metabox when editing a product page.
Complete WooCommerce Support:
WooCommerce product variations, attributes, meta data, and custom fields are all fully supported.