An OTG cable is essential to connect my Spark RC with DJI Goggles.I use it.Some other DJI drones need an OTG cable too to connect with DJI Goggles such as Phantom 4 and Inspire Series.
But DJI Store has already reduced price $50 today of both Mavic mini and Mavic Mini Fly More Combo!!!! Because of unexpected very low demand??? Mavic Mini can't replace Spark!!!
Open app on Google Play and read "More"! I also have deleted previous version and reinstalled it again from Google Play Store! I read in bottom the number of present version is: 4.1.8. I have S8+.