My primary device for navigation while exploring new regions in the Himalayas is my phone. It stores offline geo-referenced maps and contours (topography) for a large region (multiple states) and the built-in GPS receiver shows my exact location of the map. I also GPS record my journeys using Geo Tracker, a recording app to upload the newly explored trails on Open Street Maps.

Being a passionate photographer I also take lots of photos and videos amounting to approx. 1.5GB per day. I use Wordpress to blog offline daily while hiking in the mountains (and post once I get network in valleys). Peakfinder is yet another useful app which to identify (offline) peaks along the skyline while hiking.

Carrying complete offline maps I do not require a network / data connection and therefore keep my phone in flight mode to extend battery life. The battery of a relatively new phone (less than 2 years old) will easily go up to 2 days in flight mode, sufficient to cover 90% of my traverses which I fast hike in just 1-2 days.