Nice work. I have just brought the Vision Pilot app and it is good and best value in the market.
Unfortunately, my V.2 phantom does not come with the tile knob on the RC and I used to rely on the camera tilt sync function in the stock DJI app. It is not perfect solution but still a nice one after you get used with it. Take off you hand from RC and check button or doing any gesture on mobile may just trim off the capability to have a smooth video up/down panning while moving the phantom.
It is possible to have the camera tilt sync function back in place?
BTW, I found the UI for touch button in your app on an iPhone 6 is not so responsive. Usually I took a couple try to confirm a button. Not sure it is my phone problem or your app problem. Are you targeting the app for iPad usage only?