Jungle Scout - Amazon product research made easy.
AmzScope - Find profitable products for sale on Amazon in one click, relying on statistics instead of intuition
AMZScout - AMZScout extension will help you make a decision about picking a niche based on the actual data, not intuition.
ProfitGuru - ProfitGuru is the easiest way to find the most profits on Amazon.
AmzChart - AmzChart is a free Amazon analysis tool to scale your Amazon business.
Egrow - Egrow is a free web-based tool specifically developed for Amazon sellers.