Reliable AQ indicator – Beijing/Shanghai Air Quality (Data from US Embassy) Review

The app is easy to read, presents AQI data in enough detail and is reliable. It's an indispensable tool to check the health of the air before outdoor activities in Chinese cities. Would be great if it would alarm when PMI 2.5 exceeds a user selectable limit.
Review by blackcats76 on Beijing/Shanghai Air Quality (Data from US Embassy).