I have somehow not known about KeyCue until seeing your note on their update, @agen. Looks like a fantastic app! Have downloaded and will be trying it out over the next few days, but am pretty certain I’ll be buying it. I often want to learn more obscure keyboard shortcuts and this will make the process a lot smoother. Plus, the emoji picker looks vastly superior to the stuttering (at least on my 2013 MacBook Air) one that’s built-in to Mac OS. And it’s great to see TidBITS members can get a discount on purchase. 
(As a side note, I used to use Ergonis’s PopChar software back in the classic Mac days, and it was excellent, and indispensable at the time. At some point with Mac OS X I found the Show Emoji & Symbols menu extra was sufficient for my limited needs, so haven’t used PopChar in a while now. It’s nice to have another utility from the same company!)
This is why I love these software update mini-articles in TidBITS. I realise that in this specific instance I’ve missed a dozen or so previous ones about KeyCue. But I often scan the ones not related to software I use or already know, because I know there’s a high chance it will be interesting software. The signal-to-noise ratio in TidBITS remains impressively high!