A PHP wrapper for receiving payments
Cashier aims to let you take in payments from Stripe, Balanced, BrainTree, and even PayPal with a single API. All of this so you are never locked into a payment processor. Switching processors is as easy as changing your configuration file.
If you are interested in helping with this project, submit an issue.
Currently I am looking for help from developers that know a bit more about BrainTree and PayPal.