Developing IOS Application with Delphi Xe4 .only for play the toy?

Recently, i am working on r&d of some keypoint of some app idea. if all thing ok, i will continue to develop the app and submit to appstore. 

i have resolved: Use native webbrowser post customized data to some url.  social connect test.

use common ui. 

but. how can i customized the ui? like three20 .  so first stage, i have to focus on the feature. not ui .  i am try to review what delphi xe4 can do. 

and then do it. 

another issue we will face is : cross platform? if we use  too much native objective class directly, how can it run on other platform? e.g: windows or andriod ? 

if we will all use ios platform api, why shouldn't we use xcode instead? only for play the toy: delphi ?