ChemTracker predicts which aircraft overhead are leaving visible trails — in real-time. Using live ADS-B flight data, atmospheric conditions from 8 pressure levels, and the Schmidt-Appleman criterion, we analyze every aircraft within 250km of your location. Features: → Real-time flight map with contrail scoring → Sky Scanner: point at a trail, identify the aircraft → Golden hour alerts when visibility peaks → Evidence packs & field reports Free 14-day trial. No credit card. Worldwide.