This is what I -somewhat- did in the example: I've disabled it for mobile. I don't think browsers have an API to detect what power-source the underlying machine is using, though.
It is possible to detect mobile and disable it completely, but for now, because it's mostly demo material, I'll leave it enabled for mobile too. In a real-world scenario you'd probably show a message or explain why a mobile user cannot use it. That would certainly give you credits.
