Web based Iphone / Android app

I am considering developing an Iphone/Android application but I want the information on it to be live and uniform between platforms... Therefore it seemed logical to me to make it web based. I would however like to be able to achieve certain non web based functions such as adding events to the calendar and gps locations on the the mapping sortware.

My questions are:

1. Can I make a web based application that does not visually show in a browser?

2. Can I add additional functions that are not natively available in a browser e.g <a href="#" title="adddate:110911"/>Add to Calendar</a>

3. Would it be a lot of work to make such an app as the majority is web based (I mostly progam in PHP so coding for Android and Iphone will take me some tim开发者_如何学运维e to get my head around).

All of the questions are for both Iphone and Android.

Thanks

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I would recommend using a cross platform solution like phonegap (with UI sencha touch on top of it).

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You can have an app that is a thin shell over the system browser, and exposes the non-Web bits of functionality to the contained HTML via JavaScript interfaces. You will still need two different codebases for iPhone and Android, but the essense of the app will be still webby.

There's no way to manage the system calendar from Web apps neither on iPhone nor on Android, AFAIK.