Recurly - Subscription billing and recurring billing management. Recurly offers enterprise-class subscription billing for thousands of companies worldwide.
TypingDNA Authenticator - 2FA codes in your browser, secured by the way you type
Pabbly Subscriptions - Pabbly Subscription is a recurring billing & subscription management software.
Cotter - One-click phone number login and checkout
Reepay - Reepay takes care of your subscriptions so you can focus on your core business.
Auth0 - Auth0 is a program for people to get authentication and authorization services for their own business use.