Transportr is what you’re looking for.
last updated 5 years ago
not sure where you’re seeing this, latest release was in June, and the latest commit was three weeks ago.
On F-Droid
F-Droid says version 2.1.5 was released 2 months ago.
For some reason, mine only shows version 1.1.9.
There isn’t one. You need a separate app for public transport.
I use Öffi, which is incredibly good and integrates well with any mapping app you have installed, but is really only useful in Germany.
Most non-google apps are only locally useful cause nobody can integrate info about all public transport around the world.While not a solution right now, I just want to add that the general transit feed spec aims to solve the data interoperability of different transit systems. The transit system keeps a publicly accessible zip file up to date, and then anyone can pull/parse the schedule/prediction data in a consistent way across transit systems. I know in the us adoption is slow, with vendors prefering to build their own walled gardens and transit agencies lacking the vocabulary or skills to advocate for more open data/tools