The aviation niche for a device like the inReach personal messengers makes sense if you know its roots. Outdoor types operating far off the civilized grid have always had the vulnerability of no method for getting messages out to friends, family or rescue personnel. Trackers fixed this by combining GPS position with satellite communication; now the hiker’s position is known and can be sent along with text.
Floatplane and bush pilots are in the same remote situations, so a tracker has appeal there, too. But tracking is only part of the appeal. If you pair a smartphone with a tracker, you essentially give the messenger a screen and keyboard and it becomes a backwoods communicator. This is exactly what the DeLorme inReach paired with their Earthmate app offers (iOS or Android).