In the beginning I used OsmAnd for maps, its a bit wonky sometimes but the maps are high quality. Magic Earth fixed the the wonky ness but uses osm maps, is pretty great visually pleasing and can do all sorts of settings like speed assistance, lane assistance. I haven’t used it much but Organic Map looks good too, seems to have a focus on public transportation.

What do you do for calendar sync? I found I had to use an extension like DAVx⁵ to synchronize them to my phone, did you find another way?

I heard they’re pretty great, building bike lanes and such