The following observations are 1) not complaints, and 2) are with phone + RC using OTG.  I have never flown with just the phone as a remote.

Given that my primary phone is in a large case that is too large to fit into the RC holder (yes I've bought the external holder, but it doesn't fit in my carrying case with all my other crud), I bought a cheap low end phone to use specifically and only for the spark.  It's not a powerful phone.  I have observed that while the application will show video, the more advanced features (quickshot modes, active track, etc) do not function on this phone.  It simply does not react to the touch commands.  I suspect that the phone is under-powered and does not meet the minimum hardware requirements for the DJI GO 4 app.  I bet it's in the instructions (RTFM).

Last observation:  When I have used my primary phone, and when it was hot, the application again would mis-behave.  This has only happened a few times, my phone does not cronically over-heat.  But when it has happened, the app would pause, stall, crash, etc.  I'm convinced that this is not a DJI GO 4 app problem, as any application on any phone running too hot will misbehave.

The reason I think these observations are important is because new pilots (myself included) can panic or react incorreclty to such events.  If you are just starting out, help yourself by starting out in optimal situations and optimal conditions.

I ve had an occasional processor error when using an old 5S but no app crashes or delay.
I don't believe it was heat related as I was case I got the warning having just stepped out of air con in the shade and the phone was still cool

Hi Charles, I did the same as you and bought a phone, but never activated the phone.  I got an iPhone SE at Wal-Mart for $159.  It works great with the RC.  Just FYI.

well honestly im going to blame the phone more than questionable at best dji go 4 app on andriod on this one..    usually specially with cheaper android phones once they get hot they throttle back and apps can get less stable since things slow down with the processor scaling back to keep itself from overheating...  not to say more expensive android phones dont misbehave, i have S8 (non plus) and i left it in my car on a hot day, and that thing slowed way down while it was hot, took several seconds to pull up the phone app..

my suggestion is get an iPhone 5S for really cheap online or at walmart or something..  i dont know if the other iPhones gotten this cheap yet, but i was at walmart other day when i drove up to my farmhouse to get myself some food, $99 for 16GB iPhone 5S no other iPhone's in site.. but $99 if all you want is a stable platform to run the DJi Go 4 app, that's the way to go.  that or i suggest also an iPad mini 2 ($200 refurbished on apple) or later.  iPad mini best size for mission i think.. (once you see it in person anyone will agree) iOS is way more stable and less buggy with DJi apps

ImHereToCrash Posted at 2017-8-7 15:24
well honestly im going to blame the phone more than questionable at best dji go 4 app on andriod on this one..    usually specially with cheaper android phones once they get hot they throttle back and apps can get less stable since things slow down with the processor scaling back to keep itself from overheating...  not to say more expensive android phones dont misbehave, i have S8 (non plus) and i left it in my car on a hot day, and that thing slowed way down while it was hot, took several seconds to pull up the phone app..

my suggestion is get an iPhone 5S for really cheap online or at walmart or something..  i dont know if the other iPhones gotten this cheap yet, but i was at walmart other day when i drove up to my farmhouse to get myself some food, $99 for 16GB iPhone 5S no other iPhone's in site.. but $99 if all you want is a stable platform to run the DJi Go 4 app, that's the way to go.  that or i suggest also an iPad mini 2 ($200 refurbished on apple) or later.  iPad mini best size for mission i think.. (once you see it in person anyone will agree) iOS is way more stable and less buggy with DJi apps

How's the iPhone in daylight?

Charles Adams Posted at 2017-8-8 06:12
How's the iPhone in daylight?

eh, to be honest its usable.. but barely..   that being said even my 1000 nit S8 is what i would call "usable but barely" out in direct sunlight.    ultimately i just use a sunshade i got for $15 on amazon...

https://www.amazon.com/gp/product/B06XPD19K5

they do make them for smaller iPhones but i cant figure out which series does the iPhone 5S and SE..    but that is what i use on my iPad mini and it adds just enough shade to make it work good...