NOWPayments - NOWPayments is a crypto payment gateway that supports more than 300 cryptocurrencies, including fiat, and offers simple tools to accept crypto payments, like a crypto payments API, plugins, invoices.

Paymento - Simplify crypto payments with full control over your funds.

CoinPays Payment Gateway - Pay securely and quickly with crypto!

Stripe - Online payment processing for internet businesses. Stripe is a suite of payment APIs that powers commerce for online businesses of all sizes. Use Stripe’s payment platform to accept and process payments online for easy-to-use commerce solutions.

SphereOne - 1-click checkout for Web3

Slash - A "productivity machine" that forces you to do tasks 1-by-1