In Pythonista's Matlab documentation under Toolkits two mapping libraries are mentioned. Both seem to require Proj4 and Shapely that hooks into the GEOS C++ library. So I can't actually use Cartopy or Basemap toolkits. I'd pay extra for the toolkits to have all of their dependencies met in Pythonista or some kind of add-on. I can see a lot of terrific field and data collection uses with these toolkits.
I would love to be proven wrong if it is actually possible to get these toolkits to work.