Smart phones are awesome. But it would be dumb to lose a friend, a client, or an order because you’re looking at your smart phone during a conversation or meeting.
Looking at your phone in the middle of a meeting or conversation tells the person there with you they are not your priority right now.
Wait until the meeting or conversation is over before looking at your phone. Then you can actually use your time more efficiently by answering and/or reading more than one text or email at a time.