Scout is an easy to use extension tool for chrome browsers that turns your website into a significant keyword generator. By a click of mouse, you can uncover relevant keywords in your industry by choosing a website that is successful and attractive to your audience. You will be able to understand the true language of your successful audience and generate keyword ideas that you can use in your marketing strategy.
2) SpyFu: I suggest to have paid account on SpyFu. I just need to find my competitors who using Adwords and review them using this tool. It will show me what ads and keywords they are using. Note that my competitor who paid for that particular keyword knows exactly that it is important for his business including recent trends. Also using SEO feature you can input any URL and find our which keywords they are ranking for.
Keyword Overview looks at the entered term on its own and addresses expected searches per month, the difficulty of competing against Page 1 results for the same term, a rough estimate of organic click-through opportunities (versus paid ads and non-organic positions on the search engine results page), and the perceived priority that the user should assign to optimization for this term, where the higher the score, the higher the demand and a lowered level of competition.
The limit on manual keywords could be higher. I personally wish we could input 10,000 keywords at a time, instead of 200. However, I understand the costs that Long Tail Pro has to maintain each time a new manual keyword is input. Not a deal breaker, I just wish the limit was higher. (To be fair, I don't think most keyword tools have a bulk manual option at all).