I'm a bit late responding to this but having recently moved to
Kent/E.Sussex I've been finding footpaths and rights of way.
There are far fewer RoW here than where I moved from but there
are some well-used footpaths that are not RoW.
Quite a few local RoW were missing from OpenStreetmap (OSM); I've
added them wherever I've found them. I use OsMand (OSM/Android) -
on both Android and an iPhone when walking. It doesn't show RoW
differently from other footpaths - maybe other OSM-based apps do.
And it would depend on the path having been entered as a RoW in
the first place.
To find RoW I use the paper 1:25000 OS Maps, or the app loaded
with the free download you get when you buy one - which is on my
wife's phone 'cos it's bigger.
Each county has an online map of RoW, e.g. E.Sussex (mind the wrap!):
That has larger-scale maps than the 1:25000 if you zoom in - but
stops at the county boundary. I wouldn't try using on a phone in
the middle of a forest, but you could take some screenshots
before you go.
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