Depends. Let me start by addressing the HTML/javascript toolchains out there: they suck. One of my clients has experience of this. The first thing they tried wa

Depends. Let me start by addressing the HTML/javascript toolchains out there: they suck. One of my clients has experience of this. The first thing they tried was using one of those javascript/html systems. Its a fairly simple app that one would think was ideal for HTML/javascript, but it was barely usable and tech support was awful. Thats why they hired me. What platforms are your target - the "etc" you mention? Blackberry? Blackberry is still huge but by iPhone and Android standards they are hardly smartphones. How about WP7? Interesting but so far tiny. Next question: what kind of app? If its games, you use C/C++ and OpenGL for Android and iPhone. Personally, I use C# and manage core business logic libraries with platform-specific user interfaces in Silverlight, MonoTouch and MonoDroid. I have a client who wants Android and later Blackberry, so for that we do the Android version in "normal" java so we can share libs with Blackberry in the future. I don't think there's a one size fits all. The ones that do (e.g. Flash, or HTML/javascript) end up looking or running like ass.