I enjoyed using Hiker on a Vivoactive HR paired with an iPhone 7 plus.
The most useful feature for me is the displaying of the tracking trace on top of a map (using Garmin Connect on iPhone 7 plus ). It seems that the map is based on the Apple/iPhone "Maps" application. Consequently, live data connection would be required. Unfortunately, cellular or wifi connections are frequently unavilable on trails.
Is it possible for Hiker or Garmin Connect to allow an option of using maps provided by the "maps.me" app? "maps.me" is a free app for both IOS and Android. Maps for "maps.me" are stored in the mobile device and, therefore, are always available for use. Finally, "maps.me" contains more off-road trail maps than Apple "Maps" or "Google Maps".