title: How to handle iOS purchases for user-generated content?
body: <p>In my fitness application, there are two types of users, coaches, and trainees.</p>
  
  <p>Coaches create fitness programs (they decide the price and duration), and then trainees buy those programs.</p>
  
  <p>Problem is that Apple insists on using In App Purchase API - but I can't create the "packages" there since duration and price is not pre-determined by the developer.</p>
  
  <p>One suggestion I saw is creating virtual currency in app, but I'm wondering would Apple allow embeding web browser with a payment form (Braintree)?</p>