That is a nice rule to set in a bar, and a very unique idea too!

Yes, it is disconcerting to have people giving you company looking at their screens when they are supposed to be listening to you. On the other hand, someone who mutes his phone or switches it off when you have something important to say - makes such a difference!

Although it is much less than a smartphone, I do look at my tracker every once in a while to check how many steps I have done for the day.