1st experience: Samsung Galaxy J6 Plus works so far no issues. In follow me dynamic, while walking straight, the Anafi drifts right and left probably due to the compass in my device getting jarred a little as I walk.
2nd experience: About May 2019 my phone updated to Android 9. Now there is terrible lag in the video feed. I am also using FF6 v6.5.1. At first I thought the issue was wifi interference, but now I am thinking the phone processing is too slow.
3rd experience: I have FPV with no lag after I changed a setting. In preferences for the camera I changed "Display Exposure" to no. Apparently displaying exposure takes processing resources. So if you have lag issues try changing that setting it made a big difference with my device.