KWFinder

Free Amazon Keyword Tool

Query the association words of multiple foreign websites at once

If you want more traffic to your site or want to better understand what your market is looking for you should explore Wordtracker.

It's a powerful keyword research tool that I've used and am very impressed with. 

Amasuite 5 uncovers the products & keywords that will make you money on Amazon

It's a bit like an introduction to a word in a dictionary. I usually use this tool to write articles that are semantically related. For example, if the topic of an article is about weight loss, then I actually need to add "exercise" to the article. The words "oatmeal" and "calories" help search engines to understand the content of this article