The manual helps, but in my opinion there is a lot that is ambiguous and also poorly explained. There is help out there, in the form of Youtube tutorials, but I haven't found one yet that quite comprehensively covers everything there is to know about the app.
I knew about the scroll wheel that also doubles up as a button, allowing one to toggle through the different camera settings, but having had some free time to more thoroughly explore the app, I discovered something that hasn't been mentioned as far as I am aware , but might just prove very useful for those of you flying in areas of signal congestion.
After opening the app, if you tap on 'HD' at the top of the screen, a second screen opens showing Image Transmission Channels and potential interference levels that may be restricting communications between the controller and the aircraft.
The default is set on 'Auto' and the channel at 20 but it is possible to change that to 'Custom' and then using the information displayed choose a less congested channel, quite possibly resulting in better communications and a potentially much increased flying distance.
Living where I do, there is very little signal congestion here so I personally don't really benefit from it, but for those of you flying in urban areas with lots of extraneous and unrelated signal interfering with your comms, well, it may be worth checking for a less congested channel.
At the bottom of the same screen is a slider to increase or decrease Image transmission quality; a lower setting and smaller data exchange here might also improve image comms between the controller and the aircraft.
For those of you that are interested, it is explained clearly here:
Just fast forward to 10.30