Right. You still ideally need someone who knows iOS to do the iOS app and someone who knows Android to do the Android app. Because the best way to build apps on

Right. You still ideally need someone who knows iOS to do the iOS app and someone who knows Android to do the Android app. Because the best way to build apps on each one is still different. What Xamarin basically does for you (from my experience using it) is that you can now share the bits of code that are not OS-specific (like your business logic, data access layer, web services etc...). It doesn't try to hide the underlying platform from you though. It's not a solution for write-once deploy everywhere (those solutions suck anyway).