I will be more specific! I have a GPS USB dongle on my RPI, which runs PAW. This is the only GPS source on my IPAD mini. My understanding is that Collision Aware feeds GPS and ADS-B data from my RPI to Sky Demon.
I have also tried the NMEA GPS app, using the settings recommended on this thread. All I get in the spinning IOS icon telling me it is waiting for something, but SkyDemon does show little white planes and my location anyway. I am new to all of this and will now go back to the documentation to see what I have missed...
I also have a Dual GPS which I could use instead of the USB GPS, but have not yet worked out how to make that work with PAW and Sky Demon.