Globalstar is primarily used by business for safety of personnel or monitoring/ tracking of a wide range of assets - trucks, containers, of and has a few 10's of kilobits bandwidth. Because it's in LEO, it needs a significant number of ground stations as each satellite is in view of a single ground station for around 10 mins. Apple are also using Globalstar to offer their SOS emergency set service where there is no terrestrial coverage.
There is nothing secret about it!