It's a powerful keyword research tool that I've used and am very impressed with.
Keyword Planner helps you research keywords for your Search campaigns. You can use this free tool to discover new keywords related to your business.
Free Keyword Tool for Amazon, Google, YouTube, eBay, Etsy, Walmart, and Bing search.
Use the latest Google search data to provide accurate and targeted advertising
The opponent’s ppc budget and seo traffic value
Keywords hitter gives you all the keywords you should write about if you want to explore a topic.
Query the search and bidding situation of keywords on Google