Native apps allow for localizing of resources and using the full screen. Alternatives like PhoneGap allow for native HTML5/JS development. Titanium re-compiles HTML/JS to native, but you still need all the proper SDKs. Until the mobile vendors embrace web-as-native we'll never get native response out of web tools. WebOS did, but died, MS supports native HTML/JS for Windows 8 but not for phone. FireFox OS is hopeful but fringe for now.