[BenMcr]

The first one I supposed it depends how far people move around. There would have to be a cache limit, and then would the whole cache need to be updated next time the app had a data connection? Do you risk making the data usage higher because of the cache then an immediate feed?

For the second option, I suppose it could be something added as a choice. However you can end up a in a Catch-22 i.e. to use the map to find a location with WiFi, you need a location with WiFi to use the map.