fionnb
commented
6 years ago +1 from me - and I'd rather suggest generic "object tracking" instead of faces. The wide angle lens of the Tello face tracking will be very hard if the camera is away more than 2-3m because faces will quickly become very small/low-res and therefor hard to identify then.
Not sure if this can be implemented on the Android app: something similar to https://tellopilots.com/threads/face-tracking-with-tello-and-gocv.374/#post-2752 There is quite a number of face tracking projects here on Github, maybe one of them could be integrated without a lot of hassle?