Haven't so quickly gone from "woah, that's cool" to "purchase now" in a long time. This is awesome and I will use it daily.
There's a visual simplicity and legibility to the kind of straight-forward but slightly-decorated diagrams shown in the sample images. And the fact that I can now copy-paste them anywhere as well (rather than the classic "screenshot of a Miro or Paint.js board") is so cool.