inReach uses the
Iridium satellite
network, so global coverage. I use it to send
tracking points that allows people to see where we are. I also use it to send both per-formatted and basic texts. The cost is modest ... much cheaper than a full sat system. The plans are flexible, and can be upgraded or downgraded as need arises.
It also has other tools such as being able to access
weather forecasts (ranging from basic to somewhat detailed), as well as an
emergency service.
The cons are it's not a full satellite system. It's no where near as flexible.
It is a tool that does a few specific things, but does them well, and for a modest
price.