Using information on this site and advice from various contributors I've successfully upgraded the maps and Navcore on my Tomtom one and installed the Tomtom Navigator navcore and appropriate maps on my Windows smartphone.
I'm thinking of getting an iPhone. Information on iPhones and Tomtom seem rather sketchy in the section under iPhones and there doesn't appear to be anything in this, the Tomtom section.
Can anyone offer guidance about where to find the navcore ...