To be honest I don't really get why having web applications as native apps is much of an advantage... It's like having a Macrumors application and a New York Times application and a X-website-that-you-visit-frequently application on your Mac - why not just visit these in a browser?
Because native apps can do so much more than HTML, CSS, Javascript allows....
Lets take for example Apple's native Mail app... vs accessing mail from iCloud.com .... the native app has so many more features, and you don't have to be tied to a web browser to be reading your mail.
Or for example Microsoft World Native app VS Google Docs online. Google docs has some collaborating features, but besides that, the native app can do so much more than Google Docs could ever do.
Native apps just work better, because it lifts the restrictions that programmer have. The main one being that creating a Web App takes a lot of tweaking, Internet Explorer, Chrome, Safari, Opera, FireFox.. all have different standards for how they read HTML and CSS.... Now think about how IE has like 9 versions, and every person might not be running the current up to date version. No web browser supports 100% HTML 5... they all pick and choose what they support. When you program a native app, you know exactly how your app is going to be rendered.
Just keep in mind there are 30 versions of Chrome, 25 versions of Firefox, IE 6 - IE 11, 18 versions of Opera, Safari has 7 versions... and now that is just desktop versions... with the mobile market, all those browsers have limited capability mobile versions...
Go play around with
http://html5test.com and see how many versions of browsers there are for mobiles and desktop... Now think about how hard it is to make your web app work on all of them.