Call it a satellite communicator or a satellite messenger. Either way, you don’t want to go off the grid without one. In emergency situations, these handheld devices let you call for help, but most of the time they’re a conduit for texting with family or friends when cell service is spotty at best. Some even have navigation features to help you find your way. Garmin and Spot are the biggest names on the market, but since 2018, new competitors have joined the fray with more affordable options designed to work with your phone.