http://writepay.blogspot.com/2020/03/the-textbroker-solution...
I've also previously talked about the fact that I live without a car in the US and when I was researching what small town to move to and using Google maps to try to figure out how to get there, if it can't give you a full solution from point A to point B, it will not tell you "There's a train that goes to X city, but that's only halfway" and it doesn't cover commuter bus routes between local cities.
I routinely went on Amtrak's site to find out how close I could get by train and then began searching for local transit options of some sort. I eventually found a solution and a city to move to and all this, but I was homeless at the time and spending all day at the library trying to figure out solutions to my problems.
As far as I know, there aren't any good apps for "How do you get there from here without a car?" for the US. Google maps does not have this problem space sorted and they seem to be the overall best solution (that I'm aware of) for finding out how you can get there from here.