Just tried it. I was able to get to the "Transfer" page. I was able to connect to a Garmin G3X Touch, which displayed my Android phone as "Connected". AvareX showed the Garmin as "Connected", and I was able to select "Send to Garmin". But nothing happened on the Garmin. I tried to find any indication that my flight plan had been loaded (just a simple local flight plan). I tried sending from AvareX multiple times, even with the Garmin's flight plan menus open. This G3X is paired to a 530—no idea if that has anything to do with it. Couldn't figure out how to receive directly on the 530. Didn't feel great about running down the battery or running up the Hobbs, so I shut down after several attempts. I'm not an expert in the use of these Garmin avionics, so maybe I'm missing something. Is there a way to try from an established resource such as Garmin's FltPlan.com? It would admittedly be kind of nice to have this working so I don't spend $10 putting it all in on the ramp.
I can try again sometime with this setup. It would be great if all the latest production updates were also in the test APK. Also have access to GNS 430 and 650Xi if that helps. And I have a Garmin D2 Air, but I think you must use the Connect app to establish a Bluetooth connection to that.