by DavidShepherd » Tue Feb 11, 2020 12:22 pm
There is the OS maps app which can perform as a GPS handset, but you have to go to the OS website first, create an account and upload your route in to it, sign in to the app and then it should synchronise your routes.
You could also use the OS locate app which will provide your a grid reference.
Caveat is i know the OS Maps app works without a signal, but unsure if the OS locate app does or not.