You have probably looked at other options for the Google issue; is using OpenStreetMap, Wikimapia, or https://www.arcgis.com/apps/StoryMapBasic/index.html?webmap=4ed663323dde4d5bbc036b24e80fc2e2&extent=-1.3740,52.1721,-1.3740,52.1721 which I think C&RT use.
We're looking into various options - we need services that allow us to wrap their data into our pages. We're looking at openstreet map data and a modified subset of data for the UK (currently in place on Beta) but need solutions for the USA and Europe. Those services cost though and we could be looking at a couple of 100 each month just to run maps (either on Google or another third party).
It looks as if this is the way software companies are moving. Get you hooked for free then ramp up the price. There are a number of software programs which you used to be able to buy, now you have to \"rent\" by the month/year. How long till this model is adopted by Microsoft?
I'm sure Windows 10 will end up like that.
I'm looking at how much of a map server we'd need to serve our own tiles just for canalplan - even if we have to build one specifically for it.
Canal maps don't need updating regularly, perhaps only every 5 years, so costs may be less.
I found this:
Top 10 Offline Maps Apps for iPhone and iPad 2018
#1. Maps.me. Go where you want with Maps.me. ...
#2. City Maps 2 Go. City Maps 2 Go is yet another app which gives you map directions offline. ...
#3. Sygic. ...
#4. Pocket Earth. ...
#5. Galileo Offline Maps. ...
#6. OpenMaps PRO. ...
#7. Google Maps. ...
#8. HERE WeGo.
We need a html server based map service - we're playing round with Open Map Tiles at the moment - we can do data style maps as well as satellite (though this option will cost)