I think it could work with the right team and a mega budget, and likely be the ‘killer’ device that wearable devices have been begging for. Doubt any place that is begging for paypal donations is going to be the right team.
I agree, the inside of the arm would be better. I wear my watch turned inside because it’s easier and more unobtrusive for me to look at it that way.
PayPal donations aren’t bad, but it would certainly be nice if they could find a scientific sugar daddy!