I think this has changed. People used to be very particular about how their apps looked on different native platforms, like you say. But I don't think it's like that anymore. People are more agnostic now, when it comes to how user interfaces look, because they've seen it all. Especially on the web, where there's really no rules, and where each new site and web app looks different. I believe this also carries over to native apps, and I think there's much more leeway now, for a user interface to look different from the native style, as long as it adheres to any of the general well established abstract principles for how user interface elements ought to behave.