Thanks for these great responses, @Chuzzlewit69, @danbjoseph, @Nicholai_Lidow, @aurdipas! You're giving me lots of new ideas to chew on and software to explore. Hopefully others will find these resources helpful as well.
Some of the apps you've mentioned can also be launched with Collect in a similar way shown in my sample form:
- Google maps: https://developers.google.com/maps/documentation/urls/android-intents#launch_turn-by-turn_navigation
- OsmAnd: https://github.com/osmandapp/osmand-api-demo#command-navigate (can also do things like start recording a GPX track)
It looks like Google maps can do navigation between several different points but of course offline capabilities aren't as good as with some of the other tools. @danbjoseph does @OsmAnd do navigation between several different points?
@Nicholai_Lidow There will be a distance function available soon in Collect that may allow you to do some of your proximity verification possible through the form. You can track that progress at https://github.com/opendatakit/javarosa/issues/277.
@aurdipas is the Google Earth app you used https://play.google.com/store/apps/details?id=com.google.earth&hl=en ?