OK here is a chance for my first contribution to this community. ;-)
My Spark finally arrived today.
Updating via DJI assistant went smooth, without any issues.
1. I first connected it to my good old Samsung Galaxy S3 NEO.
- Android 4.4.2
- No SIM, flight mode
- I have both Mod 2.0 and Lite here, no official
- Both apps Works with OTG just fine.
- I was not flying Spark since it is dark outside. Just took it out to check GPS reception and do compass calibration - both OK.
- It DOES matter which side of OTG is connected first.
- Here is how i do it: switch ON RC, switch ON AC, wait to connect, put OTG cable together, plug thinner OTG side of the cable (actually ordinary micro USB cable with male USB on one side and micro USB on the other side) into phone and the other side into RC, phone then automatically offers to start MOD 2 or LITE, i choose which ever, wait a little bit and voila.

- Log in with a silly username and password, everything OK.
- Request for updating flyzones poped up, ignored it of course.
- tried several times, it works each time.
- 2nd time there was no need to log in.
- I can switch between 2,4GHz and 5,8GHz which is due to OTG.
- On LITE preloaded offline maps works.
- On MOD 2 maps Works if I enable WiFi so that it can downoad them.
The only thing which I don't uderstand is how can I see if I'm in CE or FCC. I don't understand that ''11 cannels rule'' or that ''you shouldn't see channels 12 and 13'' rule. Actually, there is no cannel indicator at all. All what I see is this.
But I don't care really, I'll check the range tomorrow. If I can get app. 500m reliable range and image transmission I'm happy and I have better chances to achieve that since I can select 2,4 GHz.
2. then I connected it to my daily Samsung Galaxy S4:
- Android version 5.0.1
- Both official 4.2.6 and MOD 2 on it
- I started with MOD2 and OTG connection DOES NOT work - so it is either phone, android version or having official app here also - i don't know.
- Then I decided for official 4.2.6 here. I followed suggeted Moccation trick, advised by Haggi and it worked!

THANK YOU Haggi. ;-)
- Connected with WiFi, (tried with OTG but it doesn't work), warning about FCC poped up - ignored - so I guess im in FCC with this one, will test the range- Warning to update flight zones - ignored.
- then everything was fine-
- As told, I don't understand that ''11 cannels rule'' or that ''you shouldn't see channels 12 and 13'' rule so I don't know where am I here either. There are indicator colums on RSSI graphs, i didn't capture a screen, I'll do it next time.
According to all those facts I have good chances to get reliable 500m range and image transmission - either with MOD2 using OTG and selecting 2,4GHz or with official 4.2.6, fooled with Moccation.
I hope I did at least a little payback with this.
I've got and still getting A ALOT of usefull informations here so THANK YOU AGAIN TO ALL OF YOU.