Hello, Im thinking about buying a Homepod, but since it is not even on the market in my country I have to go to Germany. I would like to know first. 1) How do you control volume? I have some iOS devices, Mac and Apple TV. 2) I know that I can hook my Windows 10 gaming PC via airplay if I'll install software on my PC. But how I can change volume on it? 3) My girlfriend have an iPad with iOS 9, can she use Homepod too and can she use it even since she has got a different apple id than I have?