This app has apparently been around for years (it's an extension of Google Trends, in reverse mode) but I never heard about it, shame on me. Basically it shows you over time which search terms correlate with a specific query (or with your own dataset).
It's a great resource for keyword research and also a nice angle to come up with potential product and/or blog post ideas.
Imagine you're manufacturing and selling tote bags.
Here are the correlations over a period of 6 weeks in the US.
Particularly interesting IMO are event venues, party hall, party venues. You could write a long form blog post explaining why tote bags are amazing gifts for party / event organizers.
Now let's say that you're selling sneakers.
There's a strong correlation with... pink color. Nice tip ;-)
Have fun in your search for strong correlations between search terms!