X (Twitter) - Connect with your friends and other fascinating people. Get in-the-moment updates on the things that interest you. And watch events unfold, in real time, from every angle.
Cotter - One-click phone number login and checkout
Google Titan - A 2FA device to protect yourself from hackers
SuperTokens - Open Source User Authentication - An Alternative to Auth0 / Firebase Auth / AWS Cognito
Rapid 2FA - A painless way to add two-factor authentication to your site
Amazon Cognito - Amazon Cognito lets you add user sign-up, sign-in, and access control to your web and mobile apps quickly and easily. It scales to millions of users and supports sign-in with social identity providers and enterprise identity providers via SAML 2.0.