Some cities will put BLE beacons in tunnels that transmit the location and then you can find your location via the strongest beacon signal. This seems like a nice way to figure that out without installing hardware!
Some trains even have modern technology called "screens" that display their current location, next stop, route and so on!
(Although in fairness they so often get this laughably wrong, and cycle through useless "remember your luggage" style messages so you have to wait like 20s to see the information you want - critically bad on a train.)
I really don’t understand why not every subway shows the next station on the screen instead of warning messages and other stuff. (And a marker for side the doors will open)
For at least months in my city, the screens in buses have been showing a "broken image" icon as part of their ad cycle. I'd much rather know about the next stop.
Ads make money, but not that much. I'm not convinced they are enough to be worth the bother. To have ads you need to pay people in sales to sell them, people to install them (now that this is electronic it is easier than the old paper days, but you need a more expensive tech person to keep them working). At best they are 5% of your gross budget, so not very significant and they often hard harmful to your riders.
Transit in the US seems to be constantly on a starvation diet budgetarily speaking so I'm not shocked small sums of money get chosen over options that would be better for their users.
What often happen is a a company comes into install and maintain the displays for "free", on the proviso that they can display ads and keep most/all of the ad money.
5% of a transit authority's budget would be a lot of money! Advertising made £158 million for Transport for London in 2019, much less than 5% of their budget.
Also doesn't help travelers who aren't too familiar with English - I always wonder how many NY-bound tourists have stepped off the train at "Newark Penn Station".
I take the train every day in NYC. Around half the time the train is brand new and has nice displays that even show you where the stairs are located in each station as you pull up. The other half the train is from the 1960s and has no information whatsoever. So yeah this app will definitely be an upgrade over peering out the window to read the station names. Even the trains with displays are occasionally wrong/not working.
This assumes you aren’t riding a packed train with people standing wall to wall in front of seated passengers. Being a shorter than average person also can make this a challenge.
(Although in fairness they so often get this laughably wrong, and cycle through useless "remember your luggage" style messages so you have to wait like 20s to see the information you want - critically bad on a train.)