Targeting/Developing for multiple mobile platforms

Question

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

• WindowPhone7
• Android - Monodroid
• iPhone - Monotouch

(feel free to edit if I missed some) Of course, it is still programming effort for UI, but main libraries of app can be shared.

We can all thank to a team gathered around Mono project and superhero Miguel de Icaza whose effort is priceless.

What bothers me is, what are the benefits of these options? Is it cost of maintaining one app across multiple mobile platforms less impediment then having to code each library separately for better performance. Learning curve of each language? Being Jack of All trades vs .NET Ninja

Or knowing that binaries of app programmed in native environment are less in size, maybe even optimized better and not to forget that you have to wait support of new platform os updates.

UPDATE: Obviously there is one more thing to consider and that is support. Since Novell is bought by Attachmate Group, all Mono team is laid off. However the core member of the team lead by Miguel De Icaza founded new company Xamarin which will reinvent Mono Mobile development tools from the scratch.

Answer 1

a big advantage is certainly the reusability of code / class libraries across the platforms. With that in mind you`re able to port/develop applications even faster, which in turn reduces the costs.

Also, because of the reusability of code, it will reduce maintenance expenses.

Answer 2

There are certain drawbacks to the Monotouch/Droid-libraries. There is a little speed setback (about 5%, so neglectable in most of the cases).

In my experience, the size does not differ that much. Much of the size is in the resources (data resources, packed images and alike - not processor usage), and most apps don't carry that much resources with them (because of loading times and the availability of much default controls on mobile platforms).

I don't think you should use the frameworks on games however. I don't have much experience in mobile game development, but the pretty different frameworks you're using in game development (XNA, Android's NDK..) and the need for system resources (processor usage, memory etc.) make them pretty useless imho.