Earlier quoted context omitted.
This reminds me of the Surface Dial. https://www.microsoft.com/en-us/p/surface-dial/925r551sktgn Being able to set the dial on the screen and just turn it is a really good-feeling workflow, though likely not for something as mission-critical as the article is describing.
What I had in mind would cost closer to $0.99 than $99.00, though. (Well, OK, $9.99.) The Surface Dial was a relatively complex Bluetooth device; it didn't work through the touchscreen itself, except to the extent that the touchscreen somehow knew that a Surface Dial was resting on it.
>On-screen detection: Touch digitizer reports the onscreen location through a capacitive pattern (Studio only)
https://www.microsoft.com/en-us/p/surface-dial/925r551sktgn?...