I guess the same applies for apps in the mobile space too. iOS Apps built using frameworks such as Titanium and PhoneGap always seem a little off.
There is an interesting discussion about this in Dan Benjamin's latest episode of the 'Build And Analyze' series with Marco Arment. http://5by5.tv/buildanalyze/8
PhoneGap apps feel very off because they're simply HTML/JS wrapped in a WebKit component, but Titanium is far different. Titanium makes native controls. Its virtually impossible to tell the difference between an app created in Titanium versus some JS crap wrapped in PhoneGap.
There is an interesting discussion about this in Dan Benjamin's latest episode of the 'Build And Analyze' series with Marco Arment. http://5by5.tv/buildanalyze/8