Yes, Webkul has many Magento2 Multi-Channel Integration Extension by which the user can sell their products on multiple platforms and generate sales and revenue.
You can check Magento2 eBay Connector Marketplace Add-on which will allow the sellers to import their eBay products from the eBay store to their Marketplace store.
Sellers can assign the products that are left unassigned during the import to any category on their own. Admin and sellers both can sync products from the eBay store to their Marketplace store.
The second Multi-Channel Integration Extension is called Mobikul Marketplace for Magento2 which will convert your marketplace store for Magento2 into a mobile app Android / IOS.
Your customers can easily purchase products on the go. They can easily explore your store through their smartphones. Sellers can see their dashboard, order history and can contact the admin through the mobile app Android / iOS.