I am not sure about your device but I have worked with others. I the old sane days you used a set of level probes to turn on and off the pump based on level in the well with a pressure switch in the tank. Then some pump guys got the idea they could sense the current in the motor to detect when the well went dry (not pumping water) and you have pump savers. Many also added a soft start feature which would limit torque on the well pipe (many are pvc and fragile) and reduce to starting inrush current. So yes they can save you money but there are other ways to get the same results. All pumps should have overload protection and short circuit protection (nec requirement) they also should have some device to prevent it from running dry. Bad on seals etc. A level probe or pump saver.