Yeah, I have a Galaxy S6 and works fine when I've lost signal. I'm using Gaia and Earthmate as I did buy an Inreach+ for piece of mind. While Earthmate Nav isn't "great" it does what it's intended for. I know GAIA you have to download maps ahead of time as well. I'm still learning the whole Nav thing, but I'm getting there. I think I need to invest in a tablet as trying to zoom and pan on a phone, Inreach or 7" screen on my Android radio is a pain. Plus then I can dedicate BT between Inreach+ and the tablet. My phone usually goes to radio for tunes.