I got the litchi app a couple days ago. I'm using an iphone7 plus and a P3S. I make sure no apps are running in the background then I turn on the RC, drone, and then the app.  I keep it in FPV mode and go out about 2000 feet.

Then the app freezes up. It won't even return home until I use the S2 switch. When it's frozen it says I have about 90% RC. I've searched the issue to death and can't figure it out.  The missions work fine it's just when I hit that 2000 mark it freezes. Anybody have this issue or know how to fix it?  

For comparison I used the DJI Go app and got about 6650 in the same spot.  

I don't know if this is helpful or not. It here's the healthy drones link:

http://healthydrones.com/main?share=IscPoD