Jungle Scout - Amazon product research made easy.
AmzScope - Find profitable products for sale on Amazon in one click, relying on statistics instead of intuition
Reviewbox - E-commerce data tool to monitor customer reviews, track online pricing, optimize AMS tools, and more from Amazon, Walmart, and other major online retailers.
Inventory Spy - Spy how many products remain on any Amazon Product’s offer listing page.
A2X - A2X automates ecommerce accounting for Shopify, Amazon, Etsy, Walmart and eBay sellers worldwide. Trusted by hundreds of leading ecommerce accounting firms.
AMZScout - AMZScout extension will help you make a decision about picking a niche based on the actual data, not intuition.