The "Moment Smartwatch," a Kickstarter project, is both decorative and practical. I may get one for my wife.
For myself, I have ordered a "Neptune Pine."

I have ordered the "Neptune Pine", delivery is promised for next week.
I don't go swimming with an iPhone either.

A better solution, used by some states, is to tax milage, determined at annual re-registrations. That brings in a share from the electrics and hybrids.

Kickstarter itself is a company. It gets a percentage of each product pledge. That may be subject to taxation, not the product purchase. IMHO.

Several computer systems are getting toward it.