Jungle Scout - Amazon product research made easy.
AmzScope - Find profitable products for sale on Amazon in one click, relying on statistics instead of intuition
Seller Spike - Make more selling on Amazon with Seller Spike.
AMZScout - AMZScout extension will help you make a decision about picking a niche based on the actual data, not intuition.
Wikibuy - Find lower prices at other sellers while you shop on Amazon
Sellics - Sellics helps you to boost Your Amazon sales.