During June 12-27 2016, I took a vacation in Iceland, circumnavigating the entire island.  This was a great opportunity to do a long-term field-test in a remote, mountainous and sparsely populated territory.

I used two phones:  iPhone 6s @ 9.3.2 and Android Nexus 5 @ 6.0.1 running Cordova Background Geolocation 1.7.0.

The results were much better than expected, even while travelling up rugged mountain roads and remote gravel-roads.

See the results with browsable map here

Cordova Background Geolocation 

React Native Background Geolocation

Native Script Background Geolocation