At least on Android, although I am highly confident the same technique can be used on IOS (just through a different app)
I only have tablets, an IPad PRO which is my main machine and an 10.1 widescreen Samsung with a SD card that has a lot of movies in mp4 format.
So for those in my situation and wondering, I have successful transferred movies through WiFi and my IPhone Hotspot from an Android device.
app used: WiFi File Transfer
Real easy, you select the file you want to transfer, it gives you a http:// address that you then copy into the Oculus Go Browser, which then takes you to a page tha basically is like a File Management system. Find your video and click download .
I first did a test run by recording 10 seconds off my IPhone camera and sending it. It, obviously, was in .MOV. When it was finished, you could run it straight from the browser which then redirected you to the Video app.
BUT ... when I later downloaded a huge mp4 ... it looks like the browser recognizes it as only a document. It wont allow you to play it.
I was very disgruntled and thought it couldn’t play my codec of mp4 and I have to convert it to .MOV (at least). Luckily, I just happened to go into the Video app itself independently and WALLA! All my videos actually were in there ready to play that the Browser did not recognize as a video.
And just a Pro Tip for those that dont know ... Your phone’s HOTSPOT can be used and as far as I know, this transfer will NOT use your data .. only the infrastructure of your hotspot, so if you have crap WiFi like me, you can quickly transfer in less then 5 minutes the video.
Some of you might already know this, but I wrote this so that those that dont know ... and for those that are thinking of buying a Go but dont have a PC of any kind who are wondering how in the heck they are going to get their movies from a tablet into their Go.