OpenID Connect Playground - Learn about the standard behind Google SSO
TypingDNA Authenticator - 2FA codes in your browser, secured by the way you type
FusionAuth - FusionAuth is a CIAM platform that is 100% free for unlimited users.
PropelAuth - PropelAuth hosts and manages your authentication.
TunnelBear - Really simple VPN to browse the web privately & anonymously.
Authorizer - Authorizer is an open-source authentication and authorization solution for your applications.