Apple has been heavily promoting the iPad for business applications. One of their biggest success stories is the Medtronic mStar application, which you can see on Apples website. What Apple isn’t talking about that it is really a cross-platform application running the same the C# code base on Windows, iPhone, iPad, Android, and WebKit.
At the core of mStar is the Common Language Runtime. The Mono implementations take the starring role, while Microsoft’s .NET is limited to just running C# code on Windows. The iOS devices (iPad and iPhone) use fully compiled code similar to what you would get from Objective C. Built on top of LLVM, the C# code is compiled and linked to the Mono runtime. All other platforms use the standard intermediate language + JIT compiler scheme familiar to Java and .NET developers.
The next layer up is the cross-platform MVC framework MonoCross. There isn’t much information available on this other than the brief whitepaper by ITR Mobility.
MonoCross requires the developer to implement device-specific views using the native toolkits. On iOS the native toolkit is exposed to C# developers via MonoTouch. On Android devices this role is served by Mono for Android, also known as MonoDroid.