This app is not sufficient. I managed to publish some of my products. When I wanted to sync my Shopify and Google Merchant database, I could not find the sync button. Instead I clicked "Publish to Google Merchant Center. Consequently Google must crawl ALL images over again (taking 3 days), instead of just updating those few products which needs updates. This leads to massive downtime for my Google advertising.
There are also room for massive improvements in the Errors section. I want to go through the denied products and see why they were denied. I get no feedback from this app, just that there are erros. I want to see all the errors and fix them. I can only see the first 25 of 800 errors. When I have fixed the errors, I want to upload them. The app does not help me in any way, except for the first upload I made, where 66% of my products where uploaded.