Scamper Jim, thanks for sharing the link. I took a look at it and searched for some cities we've been through. It seems pretty useful, but like all such list, not complete and of course it never can be as some places open and others close all the time. When traveling we look for small local coffee houses and cafes, McDonalds, libraries and visitors centers.
Like some others have mentioned we like getting away from technology when we get out on the road. It's nice to know we have our cell phones for emergencies and we use our laptop for downloading and processing photos and accessing information that we've downloaded prior to starting the trip. When we stay somewhere with WiFi we check and send email, get weather reports, research where to go next, etc.
Even if you have a fancy phone with its own built in hot spot that can connect to the internet, remember if you get off the beaten track, especially out West, there are lots of places where you won't even be able to get a cell signal at all. I did download an app for my cell phone that can be used even when I don't have a cell signal. I can search it by city and it will find campgrounds nearby. It's come in handy a few times.
Some of our friends who are very into technology wonder how we manage. I just remind them that we've been traveling and camping for a lot of years and somehow we've always managed to find where we're going and have a good time! Talking to the locals and trusting in serendipity has usually served us well.