BuiltWith - Find out the technology behind websites

Braintree - An all-in-one solution to accept, process, and split payments in your mobile app or online - from small business to large enterprise.

Wappalyzer - Wappalyzer is a technology profilers and leads data provider. Create lists of websites and contacts that use certain technologies.

PayPal - PayPal is the faster, safer way to pay online without sharing financial details, send and receive money or accept credit and debit cards as a seller

What CMS - WhatCMS.org looks at a variety of factors within a webpage to determine what CMS a website is using.

ProPay - ProPay is a multiple payment making service provider that lets its users to make payment to anyone in any part of the world.