Driving out east we saw a number of charging stations along the highway but typically at the large multi-bay gas stations, not the small independent stations. The EV owners I know use an app which shows known charging station locations and they plan their routes accordingly. Like mentioned above, stations are being added to retail parking lots as well, like our local MEC (Mountain Equipment Co-op).
Had an interesting chat with an EV owner on the way back from out east. He complained that every company required you to use their own card to access their charging station. You couldn't use a credit card like at a gas pump, so he needed multiple cards. Also, they bill by the amount of time, not the electricity used! That baffled me, as electricity is normally charged by the kilowatt hour. He said that Tesla owners paid less for hydro because their cars charge faster. A slow charging vehicle will cost you more for the same amount of electricity. How do the stations in the U.S. work?
I didn't know that on-the-road chargers bill by time, not kWh. That may vary with the age of a charging device. I'll have to remember that.
I haven't taken any road trips yet, so I'm still early on the learning curve for this. So far, I've charged up only at home, and paid by the kWh on my monthly electricity bill. When I picked up the car, the salesman showed me two apps he had on his phone from on-the-road EV charging companies. Once you register with them, they allow charging without using a card. But there must be chargers out there that may not recognize the app on your phone.
So far, I've looked into what brands of chargers are more common on the US east coast. I've now got a ChargePoint app on my phone. ChargePoint & EVGo cooperate with each other, a shared network. Those 2 seem to be well represented on the US east coast. Apparently, other networks, such as PlugShare, are more common in the US mid west. At present, where you live and travel plays a big part in all this.
When I registered with ChargePoint, I gave them a credit card number, so when/if the charger recognizes my phone, I can charge without paying directly. That app also includes a map function that shows where ChargePoint or EVGo charging stations are along my route. And it also allows me to control my home charger (also sold by ChargePoint) remotely from my phone.
My car also has an onboard GPS map system, developed by Google, which functions both as a navigation system and monitors my battery charge status. On a road trip, if I tell it my destination, it tells me when to charge up, and where I can do it. Unlike the ChargePoint app, I think it identifies all brands of chargers known to Google. And yes, the EV has a phone app from Volvo too, allowing charger control, GPS map functions, among some other non-charger features. (I remember when I spent 2 weeks as a tourist in the UK, the British say "Sat Nav" instead of GPS map navigation. I like saying that, but in the US it confuses people.)
So, there is some duplication between the EV's software and the ChargePoint app. I might need another charger app, but I'll wait until I've done at least one road trip before I choose again.
FWIW, I found this article:
Ten Best EV Charging Station Apps
https://theninehertz.com/blog/top-apps/ev-charging-station-apps-for-android-ios