I have an Etsy shop with over 200 listings and hundreds of SKUs that are repeated in different listings in my shop. I found that this is a company that's just getting started. Their customer service is extremely good, and they are still working out their kinks. They are happy to work them out with you. My shop is mid-size and I can afford a more high-powered software that functions perfectly out the gate, so I went with that. If you're bargain hunting and have a simple shop, this app might be perfect for you.
Thank you for your kind words regarding the service. Etsy and Shopify manage their inventory in a different way. As mentioned in our email communication I would be happy to schedule a meeting, walk you through our app and explain about the best practices for managing your inventory between Etsy and Shopify.