There's a phone app simply called Transit, already mentioned by ankly98, that's designed just to give you bus and train and other mass transit info. I find it a lot more convenient than using a general purpose mapping app when I simply want the damn bus schedule and not the other stuff Apple and Google put in my way to get there. It's free to use though some of the extended features require a paid subscription.

https://transitapp.com

Happily, it does recognize and show you all the invisible "transfers" where buses change route numbers while you're sitting in them, like the 212 to 238.