I will use the tool to pull in a lot of keywords related to a theme and group them into relevant topics. These topics will either become their own content page or will be combined with other topics to create a page. KeywordTool.io is similar to other tools out there such as Uber Suggest, which I've used for a long time, but it tends to produce more keywords and it provides search volume for the keywords.
The Google Keyword Tool is SUPER helpful for building a foundation for your keyword research strategy. At the end of the day, these search numbers are coming straight from the horses mouth. You can filter down to a hyper-local level and see which keywords are getting the largest search volume. Plus, with it’s integration with PPC you can get a quick idea about commercial intent by looking at the bid and competition metrics. How much are people bidding on KWs, higher = more likely to generate a return. Usually its aligned with search intent. That said, the trending data is a little less reliable. I would still use Trends to analyze the popularity/ seasonality of KW search volume.
If you're struggling to think of more keywords people might be searching about a specific topic, go to Google.com and take a look at the related search terms that appear when you plug in a keyword. When you type in your phrase and scroll to the bottom of Google's results, you'll notice some suggestions for searches related to your original input. These keywords can spark ideas for other keywords you may want to take into consideration.
I’ve found google trends to be an interesting way to see if a keyword (and by extension a niche) is growing or shrinking, and whether it’s seasonal or not. I can’t think of any other tool out there that can reliably tell you this information, so that’s really useful. Also, if you’re building a site, especially an authority site, getting onto something that’s trending upwards is a fantastic idea.
It would be great if you can provide comparative analysis of this tool with Google Keyword Planner. Since you’re using this tool so you can provide best comparison. One differentiation which I understood is that this tool works for yahoo and bing as well whereas Google keyword planner works only for Google but Google being a dominating search engine, gives the highest returns, so only this reason may not be enough to buy it.