In surfing the Web for apps, I saw that MAPS.ME got a lot of recommendations, so installed it and started to download its maps. It looks quite usable, but I still prefer Google Map, particularly for trip planning on a PC or laptop which has a bigger screen than even a recent smartphone.
So, would it be nice to share the same map and waypoints that you prepare on the PC, and to have the same route on the smartphone? And I am partial to Google maps, and prefer it over other online maps.
Yes, Google now makes it easy. I can preplan the driving route on the PC, and send it over to the smartphone. Upon opening the route, the smartphone Google Map app offers to download maps along the route, so that they would be available off-line when there is no signal. Of course I allow it to.
I then kept repeating the above for all the driving segments for each day of the trip, until I have all the maps cached inside the Android smartphone. To test, I turned off the cellular data link as well as its WiFi. The map display still worked. And I could still searched for restaurants, gas stations, etc... In the offline mode, you will not have the satellite view, but all the streets and landmarks are still there.
I now have all the maps of the areas that I plan to visit in France, Italy, Germany, Switzerland, Belgium, and the phone reports that the Google maps take up less than 2GB of memory. Not bad at all.
PS. Saw that I cross-posted with Explanade. My experience with the Android phone is much better than with the old iPhone 3GS. I don't know if it is because that iPhone is so obsolete, or because Google giving more capability to Android phones.