I do not believe it is Google Keyword Planner. 

I use Google Analytics - I have it set on my calendar to review monthly.  I also get email reports for Google each month showing activity for my site(s).

I have used various free keyword research tools over the years. I don't pay for ads on Google and don't use their keyword planner.

I look at my Google Search Console about once a week to check for any website errors and look at the analytics. It shows my most popular pages and keyword searches (queries) by users.  I already know the most popular keyword phrases from experience. 

I have also written many blog posts focused on long-tail keywords.  They attract fewer visitors but I have many of them so there is a cumulative effect.  Many have little or no competition so I rank #1 in search results.

I also write related blog posts to try to keep visitors on-site longer to reduce bounce rate and increase my SEO.  The analysis and data-driven content have made my website the number 1 Domain Authority notary website in the country.

My competition is not knowledgeable about SEO and are far behind and have to pay for advertising, but I get free organic traffic.

No, there are better tools out there for SEO keywords.  KWP is best for google ads.

Planning... planning...?  I'll think about that tomorrow.

I used it a lot in the past when I was running PPC campaigns - mostly non-real estate.

I don't believe it's that important for real estate because the keywords/key phrases are very simple and don't change much.

One just needs to target property types, areas, specific features, schools, and they'll have 99% of RE keywords.
It will keep someone busy for years.

Not right now.....but we had several sources when we did that.

I have used it.

Nope.

We are not fans of Google...

yes, I'm not sure that's it's new name but I use it.

No, it's not accurate nor that helpful (unless you're running ads).  I generally use Google Search Console, plain old google and the questions that my customers/readers ask. These all help with long tail searches.  I do pretty well on SEO and I get over 650,000 pv/month on my site.

No

I sell houses and hire SEO.

I am not.