A device which detects a child presence in a car seat and communicates an audible and mobile-device reminder to the driver that a child occupant is in the seat is disclosed. The system utilizes internal sensors to monitor various vehicle occupancy conditions to determine when a triggering event has occurred while the car seat occupancy sensor is engaged. Once triggered, the system will immediately notify the driver that the child remains in the car seat inside the vehicle, and will also sent follow-up alerts.