So the one that costs $20 (
This one) has 3 key differences that I can see (haven't forked over for it yet);
1. it does Stereo 3D extrapolation so you get some stereoscopic effect (despite have a non-stereo source...similar to what some 3D TVs will do)
2. it seems from
one of their videos that you might be able to use head tracking to control the phantom's yaw...so you get full up/down/left/right capability
3. looks like they just introduced mode to switch between the phantom's camera and the phone's camera, so you can see from your own pov. Cool...I may have to try this now
The one I've tried (just
FPV) is $7.99, does no stereoscopic effects, and has no yaw control that I can find. It hasn't been updated since my original post, and remains finicky. It can't seem to handle video dropout from the P3P and will freeze in a mpg-blocky mess, requiring me to switch to DJI Go in flight to regain video feed.
I have tried FPV camera now and there are some key differences:
FPV Camera:
• Much more stable
• Better, more comprehensive OSD showing most things you'd see from DJI Go
• Faster, adjustable Head tracking response
• Tracking seems limited at straight forward level regardless of whether the extra upward range is enabled in DJI Go or not
• Requires in-app purchase of the Goggles add-on ($7.99) for head tracking. There's currently a free 30-day trial for all add-ons when you buy the app
FPV:
• allows zoom-in such that you can fill each side (squarish, since it's half the phone screen) with the center of the video feed. Get to use more of the screen that way
• seems to be a little more graceful about easing to a stop, but this might just be a byproduct of being slow (or vice-versa)
* Also worth noting that while I'd like to try Litchi, it still seems to have no head tracking for the iOS version