+1 to using an inReach. I keep mine in my vehicle when I am driving solo on FSRs out of cell range. It sits on my dash broadcasting my location every few minutes. I can share a link to that track to friends/family so they can see where I am at. They can use a web browser to see the track and click on me via a web browser to send me a message. It also supports global two way texting so I can let my wife know I got distracted and will be late, as opposed to her worrying I am dead. You can also post directly to Facebook or Twitter which I know some folks do if they have a travel blog, or are an adventure photographer on assignment.
I often go solo fishing, and I am a bit of a fan of crappy whether (less boats, more Valhalla) so I wear my inReach clipped into my lifejacket. That way if I fall over I will be able to text my wife that I am floating somewhere in the ocean and need a hovercraft and a beer.
The device also has a quick SOS mode. You flip the trigger over and hit SOS and it immediately starts broadcasting your location to emergency services and they can text you to find out the nature of the emergency.
You can also pair the device to your phone over Bluetooth to make it easier to type out messages.
There is a monthly fee, but the plan is variable. I throttle the plan based on how much adventuring I plan on doing that month.
Well worth it from a safety perspective and as a marriage-saving device.