"PM2.5 air quality." Respectively, provide a list mode, map mode, as well as my collection, and EPA hourly data synchronization, use this APP to ensure the smooth flow of the network.# List mode: Screening can be displayed on the switch you want to see the level of contamination, and AQI / PM2.5, and can further inquiries complete information (O3, CO ...)# Map mode: After the open position, can query the location of the current index, long press "info window" can add / remove my collection, and switching AQI / PM2.5 display#my collection: Quick access to frequently used personal information