Everyday I see them and probably you do too. People, generally under thirty, walking with their phone in hand, quite often with no other visible burden, no wallet, no purse. Presumably they're ready to instantly answer a call or a text or whatever. Is there a term, preferably non-pejorative, for this behavior?
Nomophobe derived from "nomophobia"
https://en.wikipedia.org/wiki/Nomophobia "Nomophobia is the fear of being out of mobile phone contact".
The combination of the words, "phone" and "snubber" which means people who lower their heads looking at their smart phones.