I have a new Mavic and an iPhone 6 to pair with it. I am concerned about DJI apparently uploading everything to their cloud and allowing them access to all of it. Is this generally the case with the 3rd party control apps, as well? It appears folks like the Litchi App - if their phone supports it. Does it have features comparable to the DJI App? Are you aware of any articles comparing/ contrasting control apps for the Mavic? Lastly, does the iPhone have to be in range of a cell tower for the software to work (doesn't seem like it should). I would like to fly it up in the mountains of Eastern Wa. where cell coverage is 'spotty' at best.