Lydia - Lydia lets you use your card whatever you need to pay, even a friend.
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.
Noodlio - The marketplace for app development
Wirize - Payment checkout for freelancers
Xtendify - Marketplace for Open Source CMS and Frameworks.
Giftbit Payment API - Stripe for gift cards