Card payment in app for peer-to-peer payments

Dear fellow programmer. I hope you have more experience in mobile development that I have, since Im working on my first app for Android and iOS, using Xamarin.

A part of my app is user paying each other money for (lets say) services. I want to support user inputing his credit card info and a sum and the money goes to an intermidiary account.

When the service has been provided, the money goes to the destination account (the "service provider").

1) Is there any App store/Google play-policy that forbids this, so that you must use their own in app payments?

2) Which is the best way to do this, Ive stumbled upon Stripe a few times during my quest