Hi jheldt,
Yes, there are certainly applications and solutions that will help you to expand your products to marketplaces like Amazon/eBay. We work with many Shopify partners to help integrate their products to sell in these marketplaces. Decrease costs by automating your item, order and customer processes, while also increasing sales by connecting to marketplaces like eBay and Amazon.
You can learn more on our site: https://www.nchannel.com/connectors/shopify/
Best,
Mollie
nChannel