To get started with the Free Keyword Tool, just enter a keyword or search term into the relevant field. If you want to conduct competitive intelligence research into your competitors' keyword data, you can also enter the URL of a specific webpage to view keyword data for that page. You can also enter your industry and country to see even more accurate results; it's not unusual for the cost-per-click and other metrics to differ widely from one country to another, even for advertisers bidding on the same keywords in the same industry. 
Are you a business owner, online marketer or content creator? If so, most likely you would like more people to visit your website, read your content and buy your products or services. The easiest way to achieve it is to find out what your potential customers or readers are searching for on Google and create content on your website around these topics.

"I've used many keyword tools over the years and Keyword Researcher is up there amongst the most useful of them. Apart from being a great way to get ideas for content, as an AdWords consultant, I also use it to uncover words and phrases that my clients would not want to be bidding on (negative keywords). This is a real time saver for me and a budget enhancer for my clients! All in all, this is a great app and should be used by any professional search engine marketer."
The primary difference is that Long Tail Pro is a big time saver over MS. With Long Tail Pro you are able to enter in multiple seed keywords at once (rather than just 1 with MS). So, instead of entering in 1 seed keyword, waiting five minutes, then going back and entering in one more; you can enter 5 seed keywords (for example), hit generate and then see all the keyword ideas at once!
I’ve owned a dozen or so Keyword Tools in my time and most of them are basically the same, but I’ve always thought the best Long Tail Keyword research tool is the very quiet and reserved Keyword Researcher Pro. I don’t see it being shouted from the rooftops and I don’t see any aggressive marketing for it, but my…it’s a real useful tool that I now wouldn’t be without.
How do I know this? Because I’ve done it! In late 2013 I was still struggling to earn a respectable income online. I started up a keyword research service and marketed it to just this blog audience. It turned out to be quite popular. Basically – I would find niches using Long Tail Pro then create Keyword Research Packages. Each package contained usually several hundred keywords with KC scores calculated. I was selling these packages for anywhere between $97 to $147. I even sold one single package for $597! That one had very high search volumes and very low competition.
"I've been doing keyword research for years, and I can tell you that dealing with hundreds of keywords and dozens of spreadsheets is enough to make anyone lose the will to live. Keyword Researcher is great because not only does it let you easily find keywords that people are actually searching for, but it has a clean and simple interface that makes it easy to keep track of what you've found. If I'm stuck and need some new ideas, I just fire it up and usually find several things to write about in a few minutes."
Provides links to price estimate tools from Google AdWords. That Google AdWords tool showed the necessary bid to rank #1 for 85% of queries, and roughly how much traffic you could expect AdWords to send you based on that bid price and ad position, though, as mentioned above, Google has obfuscated their data in their interface for everyone but longtime AdWords advertisers.
This tool allows you to type in your keyword phrase or keyword in the field that is provided and it will generate a long list of suggested keywords.  It has three button level and you can perform a deeper search by clicking on button level 2. You will get a list of keywords or keyword phrases that are related to the original list provided in level one. If you want to continue further, you can click on level three and then click the link at the bottom to download the data. The tool can assist you to discover those keywords that your competitors could be ignoring and use those opportunities to create fresh targeted content.

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).