Does more or less what it says on the tin, though setting it up and knowing where to put the image files and so on isn't mentioned in the "installation" instructions.
One major problem/oversight, though, and the reason I'm rating it the way it is, is that the "Input History" overlay has several keyboard buttons that it doesn't register. Specifically, no punctuation marks show up when you press them.
Since I was planning to use this to make some Photoshop and other tutorials more accessible with visible keystrokes, this oversight makes the plugin unusable for me, since ctrl++, ctrl+[, etc. are common keyboard shortcuts, and none of them register. (Ironically, they do show up on the keyboard overlay, but displaying the whole keyboard on-screen at once takes up way too much screen real estate.)
It looks like I'll have to find some external solution that runs outside of OBS.
https://i.imgur.com/63G3oga.png
https://pastebin.com/ZN6zY0nq
Keycodes can be obtained by running demo_hook_async.exe in the "util" folder.