In this 1975 novel Mack Reynolds equipped every resident of Skyler Deme with a "TV Phone" that was also a "Universal Credit Card", and was routinely used to query "the computers" as well as being a RFID-like access card.
I last read
this about 20 years ago. Re-reading it now - this is probably the best
depiction of a "smart phone" in pre-web science fiction that I can think