I like this book and I’m never quite sure how some of the terms were Doctorow capturing what’s going on and writing it down vs inventing it. I think how whuffie was described here seems like something that will really exist and I don’t know if there were any sites displaying cumulative karma for people. It was at least the first time I read it. Also, I think the “comm” described in Eastern Standard Tribe is the first…
I'm sure at least somebody was thinking about that because Doctorow's books are popular, but all that specifically happened is vendors discovered if you tell people that the handheld computer you're selling them is a "phone" they'll buy that, and then of course they actually wanted a handheld computer, so they'll keep buying them even as actually they now realise they don't want to make telephone calls.
Both Android Inc. and the Apple secret project to develop their smartphone pre-date Doctorow's novel. Which doesn't mean he knew about them, but it means he couldn't have inspired these efforts.
The handheld computers aren't specifically doing those things, they can just do whatever, because they're a general purpose computer, and the features you listed are among the popular things to use that for. I guess maybe they needn't have happened to have cameras, but given how cheap that is to do it's not a big surprise.
The Young Lady's Illustrated Primer from Diamond Age is maybe more directly inspirational, various technologies are clearly inspired by the Primer which substantially pre-dates them because it's from a time (the mid-1990s) where many people don't have Internet access.