Greetings, OpenGB tribe!
I'm relieved to be able to report that I've got my OpenGB happily printing large gcode files from a $95 Windows 10 tablet using Simplify3D's control panel. You can find the tablet I used here: https://www.amazon.com/gp/product/B018X8M670/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
There are other similarly priced Windows tabs out there, but all the other ones lack a full-sized USB port. This one actually has one, as well as a secondary micro-usb port that can be used to power the tablet. It has a dedicated power port, but I'm just using the micro-usb since it's easier and can use the long cable I was using for the Pi.
The tablet is not powerful enough to preview large gcode files in the visualizer (it will crash the software), but it has enough ram (2GB) to load up all the large gcode I've tried in the Control Panel. Also, since I'm normally a Windows user, it was really simple to get my laptop and the tablet networked for transferring gcode files. Nice!
If you want to try this upgrade, I also designed a new tablet holder to attach to the existing Re3D mount. It's designed to print without support if you rotate the part so that it's standing straight up and the stl can be downloaded here: https://www.dropbox.com/s/gxwfj4o3kz1t3av/10inchRCATabletHolder.STL?dl=0
Re3D, feel free to add this file to the repository for printed parts.
Now, here are some photos of things in action: