>I watched a demo on Microsoft academy ( Viv posted a link ) and to build for iOS you need a Mac connected to your PC for the compilation to take place on - I naively thought you would design a form ( or whatever ) in Windows and the magic of Xamarin would produce a Windows app and an Android apk and whatever you need for the iOS one for you to distribute

Yeah... my boss bought a mac-mini for a couple hundred just to build ios apps.