I'm developing and app that charges the user a variable amount per month depending on the use. I've looked at the guidelines and I don't know if it's possible because most of the payments allowed are pre-paid methods. Could we do it externally? I mean, we add payment methods from a website and then the user will see the cost of every use in the app, but the user won't be billed for that until the end of the month. Thanks!

We are developing an app that allows the users to earn real money by answering questions (Other users pay to create the questions). We want to know if it's possible to have a balance in USD (real money) and allow the users to request a cash-out. I've been checking out the guidelines and I don't see any information that makes me know if it's possible or not. I know that with in-app purchases you can buy consumables but it's not the same concept, because you have a balance and you are earning/spending money all the time. Any idea about that? Thanks for your help!