The problem is: I don't want to dial immediately, I need when user taps the 'call' button, app jumps to dial pad in phone app, aand user enter's the phone number,then user can press 'Call' button to make this phone call.
[[UIApplication sharedApplication] openURL:@"tel://"]
This is not possible, however why don't you like the 'tel://' method since it keeps the user in your app once the call terminates? I haven't seen a single app that redirects to the call screen to dial a number since the call button is more simpler.