We have been doing PayPal API integrations since 2008. We have experience with all of the PayPal API solutions. PayPal offers a variety of products and solutions for accepting payments. We can help you choose the solution that is best for your requirements, whether your goal is to get up and running as quickly as possible or to develop a fully customized payment experience. We also have experience with the legacy APIs like Direct Payment Express Checkout.
PayPal Buttons are a quick way to get you started with PayPal. We have done these for many clients.
We used PayPal Invoicing for Kallzu to allow any easy way for your customers to get paid quickly.
Future Payments API allows you to save credit card data to the PayPal Vault so that customers can pay with only 1 click. This also allows you to offer your customers the flexibility of paying with any of the saved credit cards.