Hello,
there is someone that can help me to use this component ?
I tried it on localhost (mac with mamp), I tried to see the result in www.testiphone.com with URL localhost:8888/mysite but I saw the site with desktop template.
Which are the prerequisites of web server ?
There are other plug-in or component to install ? Why in my installations there are no extensions in extension tab ?
Is necessary to have a Joomla installation in subdomains ?
Thank you
Claudio

testiphone.com (also iphonetester.com and other similar sites) is not an emulator, it just a frame of appropriate size in your browser, so your site determines that you are visiting the site from PC and not mobile device.

To check mobile view either use Mobile-Always plugin, or change User Agent via Developer menu of Safari (and it's not a problem to found iPhone UserAgent in internet).

If you are running on OSX I suggest you download iOS SDK from developer.apple.com.

Running iPhone simulator is free and it gives you 1:1 visuals how the site looks on iPhone/iPod/iPad.