The tablet app is Android compatible. However it would not let me download files to an SD card. It seems to want to use the tablets own internal storage. And since the videos are quite large. This can be problematic.
Now you'd think the easy way around this would be connecting the camera to a desktop PC and using the USB port or simply removing the SD card. Neither of these options were working out for me. USB connectivity was spotty and irritating. Sometimes the camera would show me the files. And then nothing would happen when I tried to copy them or my PC would freeze.
I'm not really sure what the issue is. But GoPro Hero4 and USB transfers are just not an option on my PC.
I had similar issues with the 64GB SD card. Which actually wasn't even recognised by Ubuntu at all. It's likely my little USB adapter just can't handle it. Whatever the problem was. Ubuntu just didn't see the card at all and so couldn't mount it.
I thought I had made a horrific error in buying GoPro's. I use them while commuting to work on my bicycle. So I started looking for a solution. And found a link which described how to stream live video from a GoPro using VLC. The tutorial was for the Mac. But all it needed was a WiFi connection to the GoPro camera, a web browser and VLC. Nothing Mac specific then.
So I figured if I can stream live video. Maybe I can transfer pre-recorded videos. And I was right.
Step 1: Enable the WiFi on your GoPro using the GoPro app option and NOT the RC.
Step 2: Connect to the GoPro's WiFi network as you would with any other network. It will be named whatever you named the camera when you connected to the Android app. If you haven't done this yet. Do it now.
Step 4: Click on the video file you want to download as you normally would with any other file.
And that's all there is to it.
EDIT - 07/07/2015: Some folk might prefer this method.