GoCoin is a bitcoin payment processing service for merchants. It allows online merchants to accept bitcoin and then receive payment in fiat currency. GoCoin offers an API integration for online payment processing services that is used by many online services that accept bitcoin.

Paymium is a crypto exchange and payment processing company. It allows merchants to accept digital currency and then receive payment in fiat currency. It can also be used as a trading platform to buy and sell crypto funds. Paymium also offers an API integration for payment processing services that can be used by third parties to provide a payment method to their merchants. Paymium's platform is widely used by a variety of merchants, wallets, and financial institutions.