I've used my Phantom 4 with my iPhone 6s, my iPad Mini 4, and my iPad Pro, all with wifi and Bluetooth up and running. No issues. I did have an issue with my iPhone 6s crashing with Litchi. It turns out that I was getting a huge battery drain during a mission. If I flew with the phone at less than about 40% charge, it would suck the juice down to the point where the phone saw no battery left and just shut down. It was weird. When I rebooted the phone, it would show 30-40% battery again.