The Canadian Avalanche Centre (CAC) has categorically stated that there is NO smartphone app that could or should be used as an avalanche search tool. Specific avalanche transceivers operate on the 457kHz frequency which is used only for these devices as well as being able to penetrate snow-pack to reasonable depths.
The smart-phone apps use a combination of bluetooth and/or wifi which transmit the victim’s GPS location to the searcher’s phone.
The 457kHz frequency is standard across all transceiver devices, but the apps are neither compatible with transceivers nor even compatible with the other search apps. The CAC goes on to state “None of the various communication methods used by these apps come close to that standard,” “WiFi and Bluetooth signals are significantly weakened when passing through snow, and easily deflected by the solid objects we expect to see in avalanche debris. And the accuracy of a GPS signal is nowhere near the precision required for finding an avalanche victim. ”
Also to be considered is battery life on your phone and how it’s affected by temperature.
The statement concludes with “We are warning all backcountry users to not use any of these apps in place of an avalanche transceiver.”
While I’m sure many of us are thinking this isn’t anything new, if you have a reasonable understanding of how transceivers work and the problems encountered in avalanche search/rescue as well as the general environmental factors involved, it would be obvious that these apps simply wouldn’t be any good, but it’s good to see a respected authority on these things making a definitive statement on the matter.
The CAC’s review of the apps is here :http://www.avalanche.ca/cac/avalanche-search-apps-review
and the official statement regarding their use is here: http://www.avalanche.ca/cac/avalanche-search-apps-press-release