The chart shows all of the APIs of the Windows 8 Runtime. Blue boxes are those for which there is not an analogous API for iOS. As iOS developers surely know, Apple platforms lack NFC, "Live Tiles," direct links to SMS and other things. When in doubt about how iOS APIs map to those of Win8, Hillegass refers developers to an online map of iOS-to-WinRT functions.
Also significant, C# is more strongly typed than Objective C. "Being loosely typed lets you do some powerful things with very few lines of code," said Hillegass. "For example, creating an object from a file, [as with] a persistence layer, tends to be elegant." Having iOS core data services simplifies object storage in SQL. Implementing persistence on the Windows side requires lots of extra code. With weakly typed languages, there's less error checking by the compiler. "On iOS, you have to be more diligent about testing. Because [C#] is strongly typed, the compiler can catch more errors at compile time, which creates less buggy code and lets you find your bugs more quickly," he said.