Targeting/Developing for multiple mobile platforms with one programming language (C#)? Cost-Benefit?

Question

Today it is possible to use C# programming for multiple mobile platforms such as:

• WindowPhone7
• Android - Monodroid
• iPhone - Monotouch

Answer 1

Advantages:

• Code all in same language and (mostly) usable on each platform
• Reduced development time
• Cheaper

Disadvantages:

• Including needed libraries increases minimum application size quite significantly - if you're app is going to be large then the difference is not so significant
• Performance overhead

If you have the money and the people it's always better to have some people focused on the iPhone and Objective-C, some Android and Java etc. That way your programmers will have an intimate knowledge of the platform you are targeting and will be able to make sure your application takes full advantage of the platform's features -- an app should not be exactly the same (except perhaps games) across all platforms, you need to play to their strengths and weaknesses: an iPhone app should look and function like an iPhone app etc.

That said, if you don't have the people or the money, using a single language together with several frameworks is certainly cheaper and faster, and may give you better results than the result of strained attempt to develop for each platform individually.