The mobile browser experience
Mobile browsers lack many capabilities of mobile applications. This is because browsers cannot replicate the same native platform widgets as HTML elements. You can try to do this, but it's often better to just use the native widget rather than try to replicate it. This is partly because this requires less maintenance effort on your part, and partly because using widgets that are native to the platform means that they're consistent with the rest of the platform. For example, if a date picker in your application looks different from all the date pickers the user interacts with on their phone, this isn't a good thing. Familiarity is key and using native platform widgets makes familiarity possible.
User interactions on mobile devices are fundamentally different from the interactions that you typically design for the web. Web applications assume the presence of a mouse, for example, and that the click event on a button is just one phase. However...