Yesterday, I did the following.....

I went out packing 3 Nexus 7 2013's (NOT on the compatibiity list).. I have 2 of my own (one is slated for as a re-install for my truck) so don't curse me thinking both are for flying, haha) and the other is my son's.

My Son's (4.4.4 Kitkat with Timur's Kernal for vehicle installation) had 4.2.20 installed from last night.  First flight - latency wasn't horrid, but image got pixelated rather quickly in sports mode.  In the field, un-nstalled it, and installed 4.1.15.  Flew pretty well.

My  Truck Bound Nexus 7 2013 (6.0.1 Marshmallow completely stock) running 4.3.2 - flew pretty well, even in sports mode - I was rather surprised.  It wasn't till I got home and was reviewing flight footage that I sorted out why..... Turns out, If you have a Mavic, DJI Go 4 will allow you to enable / disable cached flights on your mobile device.  If you have a Spark, it will not.  HOWEVER, if you connect to your Mavic and disable video Cache, then power down, and connect to your spark, that "No Video Cache" setting carries over - thus, none of my flight time was cached, and thus, likely why 4.3.2 flew well.  I was playing with this cache setting thing the other night, and purposely disabled it to verify the setting stuck.  I forgot to switch video cache back on.  So I'll need to retest how well 4.3.2 flies on this setup later.

My  "Drone Prone" Nexus 7 2013 (6.0.1 Marshmallow with Elementalx Kernal and overclocked CPU's and GPU, as well as some I/0 modifications)  running 4.3.2 flew very well.  Good image quality for cached video except for the rare occurance of highy speed turns in sport mode - all in all, this is acceptable, as the footage from the cache isn't what I plan to keep - it's to help when / if there is a crash or a lost drone and I need to see what the bird last saw.

My  "Drone Prone" Nexus 7 2013 (6.0.1 Marshmallow with Elementalx Kernal and overclocked CPU's and GPU, as well as some I/0 modifications)  running  DJI Go 4 Mod 2.0 -  I am  ultra pleased with this setup.  The cached video is of excellent quality - more than what I was hoping to accomplish.  And the fact that there are new flight modes from the Mavic turned on so you can use them with the Spark... Total BONUS.  While using this App, it truly was a really enjoyable flying experience.

The next test is to see how well GO4 Mod 2.0 does with caching off and a Screen recorder of some sort on - as I'd like to have a record of every message that's sent to the display during flight - and the built in video Cache doesn't give me that.  Now that I've got a great video feed, I know that the recorded screen will yield great footage.

Where there's a will, there is a way.  I enjoy the tech junky challanges and making what I have work.  I don't like being forced to spend more cash on peripherials for an already expensive purchase - but, sometimes you have to, but I'll put up a good fight before doing so. haha.  I was willing to downgrade the app version - and even go above and beyond and overclock the tablet.

Others may just want to just have it work from the moment you plug it in - in that case, make sure you have, or are willing to purchase, what's on the compatibilty list.

Yep, I've been using an HTC One M8 with Go4 4.2.20 with no problems.

Also, recently I upgraded my phone to a Pixel 3. 4.2.20, or anything pre 4.3.x doesn't work with Android Pie. However, I installed 4.3.2 and now 4.3.4 and it works great on the new phone.

I did NOT do the most recent firmware upgrade for the Spark or the RC because of all the horror stories from that.

Yes, there are definitely lots of mobile devices that work outside of those on DJI's supported list. I keep a list of the other commonly used mobile devices here:

Best Tablets and Phones for DJI GO (Updated Daily)

Device not listed in compatibility list means DJI haven't tested those devices yet and doesn't mean it won't work.

Ryan Olivas Posted at 11-20 23:39
Device not listed in compatibility list means DJI haven't tested those devices yet and doesn't mean it won't work.

That is just half, of what it means.
If it would be just that, there would be also a list of devices, DJI HAS testet, but they did not perform well.
But they cant tell people, that a "in the drawer" android 4.4 midclass phone has almost no chance. Not before the buy, anyway :-)

This list just means, that DJI could use these phones with the Go4. In the lab.

My Motorola Turbo worked fine, especially with OTG cable.

I now use an old iPhone the Colonel dedicated to the drone. I'm not enough of an iPhone guy to find what kind it is. I just plug up the OTG, launch GO4 and go for it. I have it switched to airplane mode as once a scammer robo called the phone while I was flying. "NO MORE OF THAT!"