There's nothing magic about Apple devices. older models don't run the current version of DJI Go well.
The problems with Android are that there are many very different Android devices.
The good ones are great but there are others that aren't.
DJI Go is a very demanding program and you need to have a tablet with enough power and memory to make it run properly.
I've been running this for the last two months and it's excellent.
https://www.amazon.com/Huawei-Media...UTF8&qid=1512875759&sr=8-3&keywords=huawei+m3
It loads fast, connects every time, has a great display and is pretty well perfect.
The worst thing I can find is the position of the power switch button means I can't mount it exactly centred on the controller.
Tablet size is a personal choice thing.
I think a phone display is too small and a full-size iPad is too big and heavy to be holding attached to the controller.
An 8 inch tablet is Goldilocks just right - compact but with plenty of screen size.