Point-to-point navigation at places where you already downloaded maps is alright (same with osmand), but for exploration, or public trasnport, I would need to use moovit, mapy, osmand (wikipedia overlay is awesome), or google maps.
And in theory one could add bundles of data based on GTFS data which many transport organisations these days publish and do routing at least based on schedule times.
E.g. Motis needs walk routing data that weights hundred of gigas.
Next improvement might be to highlight lines based on frequency of service. Still possible to precalculate with little need on device.
Routing ain't easy. That's true.
Although it'd probably be good to be able to query Transitous itself when online.
[1] https://github.com/organicmaps/organicmaps/blob/master/docs/...
I tend to use the official app of the public transports wherever I am. Turns out many of them actually use OSM as a backend :-).
https://2019.stateofthemap.org/sessions/LBGPCD/
Unfortunately it didn't take off, was discountinued in 2023.