This looks interesting...
It's a hand held CNC router. You put down strips of tape with fiducials on them (no need to be precise), the on-board camera scans the area then you manually guide it while cutting and the tool adjusts itself in two axis while you cut. If you stray too far off the mark the tool quickly retracts. Accurate to 10 thousandths they say. It also does helical plunge cuts, no need to move the tool if the hole you are making is within its movement envelope.
There are more videos on their channel which goes into more detail on the tool's operation.