Yes! I've found out how to do this! I'd transferred progress from iPhone to iPad by accident, then lost it again through syncing, but I pondered on the issue and I've done it!!! Here is how:-
Turn on computer, then iTunes.
Plug in iPhone with USB cable.
Click on iPhone in My Devices
Find the bit in Summary about Back up Manually. Lower RHS.
CLICK ON Back up this iPhone to computer, and let it run it's course.
Connect iPad to computer with lightening cable.
Click on iPad in My Devices.
Go to Summary part of iTunes as before, but this time click on Restore manually.
IMPORTANT BIT!
In the box showing Restore From, scroll through to find your iPhone, don't restore from the same device.
So the Candy Crush which is on iPhone will be copied onto your iPad.
It works!
Now I just need to find out why iPhoto is multiplying my photos between devices, I think it's PhotoStream that is doing it.