SeatbeltGuard, a vehicle device, and TextGuard, a phone app, work together to help fleet managers prevent distracted driving and to monitor other driver behaviors, company officials said. SeatbeltGuard is installed under a vehicle’s dash, wiring directly to the electrical panel. When the company’s cornerstone application, TextGuard, is installed on a phone, SeatbeltGuard sends an alert to the manager if the driver uses the phone when the vehicle’s speed is above 9 mph.