A way to create applications for Windows Mobile is using the .NET Compact Framework. You can use your experience with .NET applications and languages to create applications for a Windows Mobile phone. Albeit the .NET Compact Framework has a lot of limitations compared to the full framework for Windows. That is a long story for another day…
But what about developing applications for the iPhone? Until recently the only way to develop iPhone applications is through the iPhone SDK (http://developer.apple.com/iphone/) There you need to learn Xcode, which is Apple’s Development IDE.
Now, there is a product for .NET developers to create applications on the iPhone and to release them to the iPhone App Store. Monotouch (http://monotouch.net) is an IDE to develop applications but it uses the C# syntax.
The Monotouch is only available for a Mac. Monotouch does include interfaces to iPhone APIs, such as access to GPS, accelerometer, address book, etc. It also uses the Cocoa Touch (Apple’s UI Framework) so you will have access to the native iPhone controls such as Pickers, Sliders, etc.
Here is a good article about using Monotouch on InfoQ (http://www.infoq.com/articles/monotouch-introduction). Monotouch is expensive, but it is a full development environment with the language syntax C#-like. If you are familiar with C# and want to develop iPhone applications, this is probably the fastest way to do it. On the other hand, you can download the iPhone SDK and learn Xcode and the C syntax to create the iPhone applications.
