The CityAir app - the healthiest way around London. Are you a jogger, cyclist, driver or commuter? Do you know when pollution is high or low? The CityAir app will alert you on days when pollution is forecast to be high and give you tailored advice on simple actions you can take to reduce your emissions and exposure to air pollution. Use the map to plan your journey and easily pick the lowest pollution route through the City - even in 3D! You are the key to cleaner air. This application