I'm a PPL instructor in France.

A French regulation makes it mandatory to overfly cities and towns at a minimum height depending on the size of the town.

The official regulation (arreté de 1957) says that the size of the town are shown on the IGN (Institut Geographique National) 1/500000 map.

So I must in practice teach navigation with that IGN map as it is the only source of information available.

As it is not available in Skydemon I just cannot recommend Skydemon to my students, and they go for SDVFR or Flymate instead. It's a shame as Skydemon is I think the best VFR navigation app. Once they get used to another app, they won't change.

There is little point in mentioning other apps that do include charts from third parties. We all know they exist.

Question for you Tim. Skydemon depicts cities as area and towns with dots, is there a clear definition of the criteria of such classification. My ICAO map shows cities in area >2000 citizens and below as dots only. Does that corresponds with Skydemon vector maps or not?

Next time flying in France I would then need to avoid overflying all cities depicted as an area (>2.000, hoping this follows the ICAO depiction in Skydemon, subject to Tim's verification) thus ensuring not to bust limits, alternatively bring the map specified for reference, but still using Skydemon as primary tool for planning and navigation.

I imagine the only route Skydemon potentially could take, was to offer a depiction of cities more granular, in this case >10.000 and >100.000, however this would have to be a general classification by ICAO, but this seems to be a French classification only.

I have not heard of any other country where there is altitude restrictions based on city size. Anyone?