Sure, there are standards for SSO, like OpenID Connect. Your biggest problem is just that most websites and apps refuse to support open standards, preferring to

Sure, there are standards for SSO, like OpenID Connect. Your biggest problem is just that most websites and apps refuse to support open standards, preferring to give people the choice of Google, Facebook, or Twitter. So you can easily set up your own SSO, but nobody will let you use it to log in.