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.

Mentioned in the above video is the Keyword Competitiveness (KC) feature within Long Tail Pro. With earlier versions of Long Tail Pro, you could only access this feature if you paid extra to upgrade to the Platinum version of Long Tail Pro. Pricing structures and the way the software is delivered has evolved over the years – and currently (as of the date I am writing this) all features of the software are included no matter which payment plan you choose. So right now – everybody who buys Long Tail Pro has access to this extremely powerful feature.

I just downloaded a free version of LTP 3.1.0 and I cannot figure out why I can’t see the table headers of ‘Page Authority’, ‘Domain Authority’, ‘Juice Links’, etc next to ‘Keyword Competitiveness’. Normally, I should be able to see these but instead I see new categories like ‘Trust Flow’, ‘Citation Flow’, ‘Domain CF’, ‘Domain TF’ and so on. I thought I can still use the regular version of LTP for 10 day trial so I am not sure why I see different categories. Is it b/c I am on version 3.1.0 instead of 3.0? Let me know if you have any idea.Thanks!
There, now. We’ve given you an overview of twenty-five cool keyword tools. Of course each of these has its own strengths and caveats, and at least for now, none can match the effectiveness of Google’s Keyword Tool, particularly in language, location, or device-specific results. Google gathers and analyzes vast amounts of data and as you know, the rich only get richer.
1) SEMrush - I believe that among all the 3rd party software, SEMrush has the largest keyword database. Their search volume data is pretty accurate and aligns with the Google keyword planner. Also, based on the type of content that needs to be produced (i.e. informational, transactional, etc.), one can utilize different filtering options available in it.
But it’s still very useful for getting search volume data (provided your account still shows this), which is helpful when choosing which of the many keywords you’ve found to focus on (although you should take these estimates with a pinch of salt, they are still useful in indicating the relative search volumes of different keywords, even if the absolute estimates are a little off).
Basically, Google shows the autocomplete suggestions whenever you start typing anything into Google search box. It is in Google's best interest to show the most relevant keywords in the autocomplete suggestions. Keywords that would help Google to retrieve the most relevant websites and help users find the most relevant content for their search query.
Most people who use the Google’s auto complete feature to generate keywords that they include in their blog title or page find Soovle to be a very useful tool. This tool moves the auto complete feature a step forward by getting inputs from several sources like Amazon, Yahoo, Wikipedia, Bing apart from Google itself. This assists the user to generate keywords that drive online traffic in a better way. The default is usually set to Google but you can switch to the other options at your own will and view how the outcome keeps on changing. You can experiment with a broad range of keywords by running them through a specialized tool such as the keyword inspector as a way of extracting value that will boost your sales on Amazon.
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).