OpenStreetMap (I use organicmaps as a client) is not a viable alternative to me when there is no reviews and no information about departure times. Are there any alternatives that are open-source?
HereWeGo probably the best till now but not open-source.
Edit: wrong spelling of OpenStreetMap
All alternatives here are pretty good. Recently there was another app released its called Transportia. https://github.com/Wafler1/transportia. It has nice UI, but could be a bit buggy