Wordstream is a free keyword tool that makes it easy and fast to get those keywords that your business needs most in order to drive traffic through paid and organic search.  All you need to do is enter a website URL or keyword and you will get hundreds of relevant keyword results that are tailored to your country or industry. Every keyword has an estimated CPC, competition score, and a proprietary opportunity score that will assist you in budgeting for your online campaigns. You can download your list in a CSV format and upload it in AdWords directly and begin to work on your new campaigns.
However, KWFinder has a couple of areas where Longtail Pro outshines it. Firstly, I like the fact LTP provides you with a suggested keyword competitiveness to target (as described above). More significantly, I don’t like the way that KWFinder restricts your number of keyword suggestions if you choose their cheaper pricing tier – it feels like they’re holding back some of the power of the software unless you pay more. With LongTailPro, you can see as many keyword suggestions you like so long as you’re within your monthly allowance.
One possible problem is that although the Keyword Planner has some cool new features (including integration of the Google Traffic Estimator, which will be retired too), as of this writing, the indispensable Exact Match and Phrase Match features are nowhere to be found! Whole books will become useless without these, so I hope Google will eventually port them to the Keyword Planner. Nor do you see the “Include specific content” option, which is a life-saver for the adult industry, which spends the most on Google PPC.
2. The second category are keyword tools based on the competition. One of the first things to determine is not only who the business competitors are, but who the SEO competitors are. Keyword research can be done by simply doing research on high-performing competitors. Some of my favorite domain-based keyword tools are SEMrush, SpyFu, and BrightEdge's Data Cube.
In a nutshell, Long Tail Pro helps you quickly find keywords in bulk based on a seed keyword that you input.  In addition to returning hundreds of related keywords, the tool also shows search volume (monthly search volume), advertiser bid, number of words, rank value, and my favorite Keyword Competitiveness (helps you judge the competition and keyword difficulty).