STPView is a custom UIView component that abstracts the lower level Stripe APIs. It'll deal with formatting credit card numbers, validation, and securely sending off the card data to Stripe.
This repo also includes the Stripe iOS bindings. The Stripe iOS bindings can be used to generate tokens in your iOS application. If you are building an iOS application that charges a credit card, you should use these bindings to make sure you don't pass credit card information to your server (and, so, are PCI compliant).