The app, which was unveiled on March 16, was designed by King’s College London and works by checking the air quality in the neighbourhood.
The Lewisham app, which is now available in the Apple and Google stores, helps users determine the best routes for walking and cycling to avoid being exposed to air pollution.
Councillor Sophie McGeeovr, Lewisham’s Air Quality Champion, said: “'Lewisham Air’ is a brilliant example of how technology can help us reduce our exposure to toxic air.
“The mapping tool plots the quickest routes from A to B while avoiding main roads and the highest levels of pollution.
“Lewisham Air is quick and easy to use and it will enable everyone who downloads the app to take action to make our air cleaner.”