In itself a very good app if you sell in one language and in one country and don't use Markets. Just unfortunately out of time.
An absolute disaster in Shopify communication and knowledge. Don't understand the basics of Shopify Markets and after over a week they haven't managed to get the right domain mapped to the right Shopify Market on Google Merchants. I will try out another app.
To be honest, I find this app to be more difficult to understand than Google Merchant Center itself. Unfortunately, credit card was charged after trial period (missed it by one day), but that's how it goes these days. From now on, I'm only signing up for trials WITHOUT a credit card! If your app is that good, you don't need my credit card upfront.