Thanks Mostafa. I can't install Onedrive now - went to Google play and it's there but the Install button is greyed out.
All I want is to get a Documents folder back on the Home menu! Sounds simple, but apparently not. All my Documents are still in my laptop, I've tried without Wifi and they are all still there, but the yellow Documents folder icon has gone. When I search for Documents I get a blue icon instead, and I can open it but can't move it. So frustrating.
Thanks anyway.