Yeah, I can't imagine a dice rolling app not being made for it.
I totally wear a watch still. I hate the idea of digging in my pocket for a phone just to check the time. Plus more and more often, I find phone usage to be disapproved of in social situations.
Smart watches depend on companies persuading people that's a form factor they need. Wearables are going to be the next big thing, and glasses have failed. There are plenty of smart watches out there, but I think it will be Apple's one which determines if they're going to be a "thing" or not. They're good at growing newish market categories.