I'm looking at using Xamarin for building both IOS and Android native apps. I would like to be able to read and query map services as well as JSON files, and Identify results in a tabular format. But more importantly, I would like to be able to pull much of the data offline for support in "offline mode" (may app will be used in the wilderness areas). I'm trying to get a feel for how much of my code can be used to support both IOS and Android applications vs. the amount of code I would need to rewrite to support IOS and Android differences. Is 20% reasonable? I would also like to get a feel for how many folks out there have done this using Xamarin, and how successful this has been? Is this technology ready for "primetime"? Thanks for your help.