Can anyone tell me roughly what would be involved in creating an Android app based on the existing Zimbra mobile web client?

The reason I ask is because since Android doesn't support CalDAV, there's no way to get Zimbra calendar notifications on Android if you're using the Open Source version.

So I figure if you create something for Android that is kind of similar to Zimbra Desktop, only without the local message store you'd be able to interact with Android's notification system and not have to create a whole new interface.

I reckon a similar client would also work for stuff like WebOS, etc.

To quote my favorite Top Gear presenter, how hard could it be?