title: Feature temporally free in iphone app
body: <p>It's possible to have a free feature in my iphone game and then charge people for it after some time trough an in app-purchase?.</p>
  
  <p>Also, It's possible to change the price of an in-app purchase after it goes life ? ( for example, make an in-app purchase free and then change its price weeks ater the purchase went live).</p>