In chemistry labs, it's quite common for solutions to be stirred with a little magnetic stir-bar with a rotating magnet under it.
Hang on, let's let a proper chemist explain:
Watching this, it seemed a bit complex to me... to start with electricity and then generate switching magnetic fields to rotate a spindle, then use that to rotate a magnet to turn a piece of magnetic material.
I wondered if it would be possible to turn a magnetic stir bar with the sort of rotating magnetic field used in some of the brushless DC motor projects I had been looking into.
This would be easier than a full-on BLDC project too... because they tend to require very high speeds and a magnetic stir bar is rather sedate compared to that.
I suppose this is what you could call an "induction stir plate".