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.
Wisesheets - Get stock financial data instantly on your spreadsheet
TrueLayer - Simple Bank APIs to access real-time financial data
Quandl - Quandl is a platform for financial, economic, and alternative data, serving investment professionals.
ACH payments with Stripe - Accept bank payments with a few lines of code.
Teller API - A single API to connect your app with any bank's account