The Navigate action is a pre-configured link that opens a native navigation app on mobile devices. The Navigate link appears only when the user is online, offline, and when activities have resolved coordinates.
These links are pre-configured:
Android devices (browser user agent mask = *Android*) open a navigation application by geo: protocol for Android browsers.
iOS devices (browser user agent mask = *(?:iPad|iPod|iPhone)*) open Apple Maps.
All other devices (Browser user agent mask = *) open maps.google.com.