During my recent visit of Crete and Sfakia, my wife and I had planned several walks.
Since google maps is not great to navigate for walks and hikes I looked for smomething better
In the Play Store (android, not apple) I found the app Map of Greece offline.
So I downloaded it, installed it and I used it three weeks on Crete.
The app is free and comes with some adds. If you pay 2 or 3 euro the adds are gone
As the name allready indicates, you use it offline which means the maps are actually on your telephone or tablet. The app allows to be located on your additional sdcard so it doesnt take space from your internal memory. (It is about 260 Mb in total).
So using the app doesnt use any data from your data contract with your provider. Roaming can be turned off) You only have to swith your gps on and thats free.
If you use the app you will see your own position on the clear detailed map as a bright blue dot.
And if that dot is on the red walking trail you are on , you know exactly where you are and where you are heading.
And that is the great thing about this app. Lots and lots of walking trails in the sfakia area are present, which makes it much better than google maps.
We walked the Kakos Poros trail starting in Ag. Ioannis and it was perfect. Even the hard to find turnoff to the Selluda (somewhere mentioned in one of the topics) was easy to find.
I include a screencapture i just made back at home , so there is no blue dot indicating my position

Try it and enjoy!