I have created a custom magento code (Magento Ebay Feeds) which can export magento products to csv and that csv can be easily imported to eBay. My extension allows to import products, pricing, description, images and more data from your “Magento Store” to your eBay. The Extension can export simple and configurable products transforms them into eBay compatible csv format. Imported products start showing on your eBay store instantly. You need to simply import that csv to your eBay store.
This extension is similar to
Ebay2Magento – http://magegaga.com/ebay2magento.html
eBay Integration - https://www.magentocommerce.com/magento-connect/ebay-integration.html
Please let me know if you are looking for Amazon Integration for Magento like - https://www.mag-manager.com/magento-amazon-integration/