1. Create route in Google Maps “My Maps” section. You can create waypoints, notes, alternate routes, etc.
2. Share the map and copy the URL link to your clipboard.
3. Convert that URL to a GPX file at GPS Visualizer:
3.A) – click the download link there, it saves a GPX file on your computer.
4. Email that GPX file to yourself.
5. Install OsmAndMaps on your iPhone or Android phone.
6. Check email on your phone. Open the email, tap the attached GPX File.
7. Choose “Open with OsmAndMaps application”
Enjoy. Once the map is loaded into OsmAndMaps, you can follow it even with no cell signal, anywhere.
Hat tip to the pace podcast, and their listener Chris Duffey, for this method.