I may be building a mobile app for a client soon. Their primary focus is the iPhone, but my boss would like to be able to target multiple platforms if it's feasible. The app will probably be a large but technically simple business application backed by a web service. So, here's the question as I see it:
What is currently the strongest cross-platform mobile development tool that supports iOS? Would you choose it over native development tools? If you choose native, contrast it with a cross-platform tool you've used.
In addition,
For a project of the type we're expecting, what's the level of effort for your chosen tool versus other tools?
What's the actual level of support of the tool for other platforms and their unique look and feel, capabilities, etc.?
How thorough is the documentation of the product?
How well do you like the development experience itself, e.g. the language, tools, documentation? Is it something you would choose to do long-term?
I'll put a bounty out unless I get fantastic answers.