First I bought this adapter from nFlightCam. It didn’t work properly— my phone didn’t recognize that it had a mic plugged in so all I got was loud propeller noise. After testing it, I sent three mails to nFlightcam customer support (since they don’t have a phone number) and got no response.
Then I ordered this adapter from Squawk Shoppe. Immediately after placing an order, they offered to connect me with their Facebook bot for order status, which worked flawlessly. I got the adapter when promised and it worked perfectly.
Then, just before a cross-country plane trip, nFlightCam answered my support email and offered to send me a replacement. That was 13 days ago and, you guessed it, no replacement has arrived.
Executive summary: don’t buy anything from nFlightcam; despite their heavy advertising, their customer support is slow and unresponsive and (at least for me) their build quality suspect. I see from reddit that other users have been happy with their products so YMMV.