Based on a conversation with someone who worked on the UIWebView-based Facebook app, there were no real productivity gain either. The web app inside the native wrapper was an insane byzantine mess, as is often the case with this sort of app.
Did it different significantly from the mobile site? From the looks of it, it shouldn't be that complicated at all. 2 views in a carousel (sidebar and the main list). No transitions, no real attempt at being app like. Doesn't look like it should be that complicated to build.
It seems pretty straightforward on the surface, for sure. However, considering just how convoluted phonegap, weinre and friends can get, it's not hard to believe it turned into a mud ball.
