I'm now running a woocommerce site, and looking for a plugin to generate XML file for it. So i can submit to the Google shopping. I have search the wordpress and the free plugins got very bad reviews ...
I'd recommend Product Feed PRO by AdTribes. The UI is very easy to understand, there's no pre-filling of fake shopping attributes as in case of some Shopify plugins and the free version is more than enough for basic feeds.
If you are using Woocommerce, I suggest using the WooCommerce Google Product Feed official extension. However you do have to pay for it, currently $79 for a single site. I've used it on dozens of Woocommerce sites. I also recommend using the WooCommerce Google Analytics integration, which is free, to enable easy set-up of ecommerce tracking in Google analytics. Whatever you choose make sure you have all the required attributes added to your products as per Google Product Data specification - https://support.google.com/merchants/answer/7052112?hl=en-GB
ELEX WooCommerce Google Product Feed Plugin This is one of the best free WooCommerce Google Shopping plugins that you can install on your WooCommerce store. The plugin helps you generate XML, TSV or CSV files with all your WooCommerce products that you wish to upload to Google Merchant Center.