Hi.  I have flown my Spark with my Google Pixel 2 phone with the Spark controller many times, with no issue.  I have seen a few videos on YouTube, however, where the host has used a USB cable to connect their phone to the controller, during flight.  

In this case, is the cable being used instead of the normal Wifi connection between phone and controller?  If so, what are the advantages?

Thanks!

Hi there, the latest firmware has been added compatibility to use an OTG cable to connect the Spark remote controller with an Android mobile device.You may refer to the release notes from DJI official web:
https://dl.djicdn.com/downloads/Spark/20180719/Spark_Release_Notes_EN.pdf

Hi,

Yes, the OTG cable replaces the Wifi network created by the remote.
Wifi always creates a bit of latency (lag time) between "real world" and video seen on your device.
On my phone, it was in the range of seconds, very annoying. The OTG cable fixed it.
But it all depends on your phone.

Cheers,
Wolferl

Wolferl Posted at 4-14 01:54
Hi,

Yes, the OTG cable replaces the Wifi network created by the remote.

Wonderful - thanks for the replies.  If I am happy with the performance with my Pixel 2, I guess it just might be more reliable in general for me/

I think it depends on your phone...  I don't see any advantage with using the OTG cable with an iPhone at all.

basically better connect to the controller to the phone, replaces lag as well