Google Payment API - Enable an easy-to-use checkout experience for customers

Expensify - Import expenses directly from a credit card to create free expense reports quickly. Approve reports online and reimburse directly to a checking account with one click.

Giftbit Payment API - Stripe for gift cards

Abacus - Expenses without the 'expense report'

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.

Zoho Expense - Automate your expense reporting process and streamline the approval flow.