In reply to Tricadam:
> Fiona, thanks: amazing tip! Do you know if there's anything like this available for Scotland?
The Outdooractive app or webpage seems to let you add slope angle to OSM maps. I tried with the mobile webpage:
https://www.outdooractive.com/mobile/en/tours/
and basically if you click on the map icon then select your type as Winter Activities -> Ski Touring then scroll to Scotland and search for something like Sgor Gaoith once the map shows Scotland or zoom into the area you want and you should be able to add the overlay via the layers icon (bottom right on mobile webpage) and under additional layers at the bottom of the menu you should have a slope overlay option.
I picked Sgor Gaoith as there are some nice steep cliffs next to it. Unlike the Alps much of Scotland is sub 30 degree so appears white with no shading.
Post edited at 14:20