Took a full flight with my Mavic and the Litchi app without a hiccup. I then loaded the second battery and wanted to see how the Go4 app would behave. Flew around for about five minutes. I think there is a new, constant center focus feature. I brought it back in, and then sent it about 150 directly above me. That's when the app just quit. Luckily, I still had telemetry on my remote. I really don't know what tablet holder folks do when their app takes a crap and their tablet blocks the telemetry screen. Anywho..., I was able to bring it down, but I won't be using Go4, other than for firmware updates.