I use my Android phone to control J River Media Center on my PC using the J River developed app Gizmo. It does not run on iPhones. There are iPhone apps for this, but not from J River. So, you may want to narrow down just what you want to control and see what apps are out there for the major ones.
Smartphone for the audiophile?
Android vs Iphone. Is the Iphone the obvious/only choice? I am thinking in terms of pc audio control apps, direct streaming, plug in portable hi fi, mobile ipod music, in vehicles, internet radio, output to DACs etc. I realise this question depends on many factors, but in general, which serves the audiophile better, and why?