Here is a quick look at what's available (these are just a few of what's out there)
Off Grid Text Messaging
Sonnet : just coming to market, in my opinion this device is better than all the rest, works with your existing smartphone (check for model compatibility) it will allow off grid text - off grid map location share - off grid data share including photos,, it's the least expensive and does not require a licence or a subscription
goTenna : available now, has wide product distribution world wide, awesome little mesh system works with your existing smartphone (check for model compatibility) allows offgrid text and map location share basic stuff does not require a licence or a subscription, advanced features requires monthly fee.Beartooth : available now, expensive, has a whole lot of range, walkie talkie feature, works with your existing smartphone (check for model compatibility) allows offgrid text and map location share basic stuff does not require a licence or a subscription, advanced features requires monthly fee.Fogo : available now, expensive, has doubles as a flashlight, has walkie talkie feature, works with your existing smartphone (check for model compatibility) allows offgrid text and map location share basic stuff does not require a licence or a subscription, advanced features requires monthly fee.Garmin inReach SE+ : available now, well built, very expensive, satellite communication works world wide, requires monthly fee.SPOT X Satellite Messenger : available now, NOT well built, very expensive, satellite communication works world wide, requires monthly fee.