This Amazon sales channel app is developed by Codisto and can help you create and manage listings on any global Amazon marketplace. You get a real-time sync between Shopify and Amazon, keeping your inventory and product details in sync. Moreover, receive and fulfill your Amazon orders directly through Shopify. Additionally, you can contact their 24×7 global support via email, phone, and in-app live chat.

Best of all, the app is totally free for stores with up to 50 orders per month. Paid plans start from $19 per month with a 30-day free trial.