ExportYourStore.com is a multi-channel solution that enables sellers to use their main store as a source of product information. They can export and sync products, new listings and updates from any marketplace with full automation and advanced rules to customize listings and prevent overselling.

Support 
eBay 
Amazon
Etsy
Poshmark
Shopify
And more ...

Features include:

Automatically or manually export and sync new listings
Create new ASINs on Amazon
Variations support for all marketplaces