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

Chargebee - Chargebee lets you manage subscriptions and payments at scale, handle custom recurring billing scenarios, reduce subscription churn and simplify accounting.

Auth0 - Auth0 is a program for people to get authentication and authorization services for their own business use.