Found this interesting article on 5 alternatives for developing native iOS Apps and of those I narrowed it down to Xarmain or course and one other, Rem Objects C#, that’s up and coming that I would love to try.
Xamarin
Previously known as MonoTouch, Xamarin is the 800-lb gorilla; its creators claim that nearly a million developers use the platform, which lets you create native apps using Xamarin Studio IDE on Mac or via a plugin for Visual Studio on PC. In the latter case, you still need a Mac on the same network as the PC. You can debug an app running on an iPhone that’s plugged into your Mac from Visual Studio on the PC, and it not only works very well, it’s as fast as debugging a PC program.
Xamarin uses ahead-of-time compilation to turn the C# code into native ARM code and adds a small 3.5 MB runtime. Cross-platform aside, the platform’s big benefit is access to the .NET technology (think of LINQ, Generics, Tasks etc.), and how it simplifies enormously the task of developing complex code. I’ve written code that performs string searches on lists of over half a million elements on an iPhone 5 and the response is almost instantaneous.
Rem Objects C#/Oxygene
A solid Xamarin alternative for developing in C# is Rem Objects C#, which is clearly targeting Xamarin. (It’s Oxygene product for Object Pascal is also very good.) Nowhere is this clearer than in their definition of native, which includes not just compiling to the platform’s byte code but also having the look and feel of the platform. (That’s an indictment of Embarcadero, which uses the same FireUI on all platforms.)
In addition to this, RemObjects also offers Silver, which lets you use Swift to write code to run against the .NET, Java, Android and Cocoa APIs. It’s currently in Beta.