For Android, the GPSLogger app is effective.

For iPhone these suggestions were offered in the misc.phone.mobile.iphone newsgroup.

Date: 22 Feb 2024 07:26:20 GMT
"Try GPX Tracker."

Date: Wed, 21 Feb 2024 17:32:36 -0600
'I use the free version of Gaia for daily hikes and biking, as well as planning things in mountainous regions. It's really very good. https://apps.apple.com/us/app/trails-outdoor-gps-logbook/id913277014
To run it "free" just copy your recorded trails to the Notes app on your phone to keep the number of recordings under 5. Then of course from Notes you can upload to programs such as Google Earth quite easily. https://www.gaiagps.com/'

Date: Wed, 21 Feb 2024 20:25:06 -0500
'I use "Trails". Free as long as you keep the number of recorded tracks to 5 or less (in the app on your phone). Once you export a track to your computer (in various formats) and delete it from your phone, you're good to go. If you're traveling, then export the track to Notes, and delete it from the app to keep the number of files managed by the app to 5 or less.'

Install an app. Adjust settings to taste. At the beginning of the route start recording. At the end of the route stop recording and store the log in a file. That creates a trace file.

Find a digital map allowing editing. OpenStreetMap is effective.