AirPolution

Presenting real-time data (from the Sensor.Community’s global sensor network) for the levels of atmospheric particulate matter (PM10 and PM2.5), outside air temperature, air humidity and atmospheric pressure... on a detailed map from OpenStreetMap.
You can save locations and then quickly see their data on the "Favorites" page. 
You can also get notified for changes in PM10 / PM2.5 levels.