An application called "AirCare" ('MojVozduh') has been launched by local eco activist Gorjan Jovanovski to help citizens track pollution levels. It uses a traffic light system, with purple for heavily polluted air, red for high levels detected, amber for moderate levels detected, and green for when the air is safe to inhale. The application relies on both government and volunteer sensors to track hourly air pollution. Unfortunately, government sensors are frequently inoperable and malfunctioning, causing the need for more low-cost, but less accurate, volunteer sensors to be put up by citizens. Faults on government sensors are especially frequent when the pollution is measured is extremely high, according to the AQILHC (Air Quality Index Levels of Health Concern).