The Google Earth app for iPhone has been updated and now allows you to load KML files, of which there are a great many useful ones here:
https://www.caminodesantiago.me/community/resources/categories/camino-gps-tracks.60/
You can download the files you want and then get them to a location in the cloud that your iPhone can access - I used Dropbox, but also have access to iCloud and Google Drive, which can be used.
Once you've selected the KMLs you want and put then in the cloud, launch Google Earth. Go to "My Places" in the menu, and at the bottom of the screen that appears, tap "Import KML file". From there go to the cloud storage location where you dropped the KML file.
If you haven't installed the Dropbox app and that's where you stored the KMLs, you will need to do that before gaining access to it on your phone.
There may be other ways to access the KMLs on your phone, but that's the way I know that works.
A good resource to have, I think.
https://www.caminodesantiago.me/community/resources/categories/camino-gps-tracks.60/
You can download the files you want and then get them to a location in the cloud that your iPhone can access - I used Dropbox, but also have access to iCloud and Google Drive, which can be used.
Once you've selected the KMLs you want and put then in the cloud, launch Google Earth. Go to "My Places" in the menu, and at the bottom of the screen that appears, tap "Import KML file". From there go to the cloud storage location where you dropped the KML file.
If you haven't installed the Dropbox app and that's where you stored the KMLs, you will need to do that before gaining access to it on your phone.
There may be other ways to access the KMLs on your phone, but that's the way I know that works.
A good resource to have, I think.