I have committed my Paypal Widget and Paypal Back-end in the App Store. For payments with bank and any creditcard over the whole world in multi currencies. Paypal is the most used payment provider of the world. Our widget and back-end module is currently waiting for approval, and after that it will be commercial available to everyone. We've used it in anonymous forms that we integrate in a existing website.
IDeal will only work for Dutch banks and the transaction costs are higher. The advantage of IDeal is that almost anybody can use it within the Netherlands.
We have a very nice iDeal module in the appstore.