AvTraffic takes a feed from the following sources.
This uses app-to-app communication and is the same as the mechanism used by the EFB providers to show their internal traffic.
ADS-B traffic relies on the feeder network of ADSB Exchange. If you go to their website and move the map to your current location, all the traffic you can see in that area will also appear in AvTraffic.
FLARM traffic relies on the feeder network of OGN. As above, if you go to their website and move the map to your current location, all the traffic you can see in that area will also appear in AvTraffic.
Traffic from all the sources above is amalgamated and merged.
You can see how many aircraft there are by checking the Status View. Tap the menu icon and select System Status or tap the status button.
Once all the traffic is amalgamated, it is displayed on the traffic view. You can tap on individual aircraft to see more details.
The amalgamated traffic is constantly being monitored and will produce a visual and an audible alert if the calculated closing time of a conflicting aircraft drops below 90 seconds. A more urgent alert is made when the closing time drops below 45 seconds.
When the app is in active mode, traffic messages are broadcast internally to other apps running on the device.
A compatible EFB app running on the same device will pick up these messages and display the aircraft as if the messages had come from an external GDL90 receiver.