Application of the "gift of this application."

Hello everyone,
I see some applications which have a Mini on iOS this application, click on this, it will cut out and then applied to the Safari adjusted.

Will this be so achieved? There can interface directly support the "Get this application", the program simply call again?

Or? ? ? ?
Reply:
Free to say, given a URL directly on it
[[UIApplication sharedApplication] openURL: [NSURL URLWithString: @ "http://itunes.apple.com/app/appname/idXXXXXXX?mt=8"]] ;/ / @ "free version"
App charges you also need to give people a promotion code
Reply:
https://buy.itunes.apple.com/WebObjects/MZFinance.woa/wa/giftSongsWizard?gift=1&salableadamid=449735650&producttype=c&pricingParameter=STDQ

I have an application using this. If you want to change your application looks to replace
salableadamid, but beyond that, there is something changed?