Thank you. Yes, I downloded My Tracks which the interweb says is all things to all men, but it wouldn't recognise either the GPX or the conversion to KML.
Thanks Stuart. I downloded that and it works well, as long as there is a signal. Unfortunately I'll be thrashing around the remoter parts of the Yorkshire Dales where masts are verbotten so signals are non existent.
I downloaded "Offline Navigation", but that's a massive file. Promo said I could navigate anywhere with it, but it won't let me import anything. All I can do is select a destination.
I can view the KML in Google Earth, but the mobile version won't resolve close enough to show all the minor road junctions when off line.
I have a venerable old Garmin Legend GPS which does work well and will do what I want, but it has a habit of switching itself off for no apparent reason, and with no warning so I'm looking for a reliable alternative.
Don't know if the new OS maps work on a phone with no signal, but they are nowhere near as good as the original Memory Maps; I have the full set of these in all scales down to 1:10,000 so can't really see the point of buying newer and inferior stuff.
I might have to resort to printing out paper maps!