i have both a garmin wrist gps and the gaia app for my iphone. each has their own advantages / disadvantages.

i've found that with gaia if i initiate the app, find my location, then go into 'airplane' mode, the battery drain is much slower. it only uses the internal gps.

i am using gaia to assist in surveying trails damaged by the Thomas Fire. it was especially helpful when the trail was completely obliterated by mud / debris flows.