Parse - Build applications faster with object and file storage, user authentication, push notifications, dashboard and more out of the box.
Google Authenticator - Google Authenticator is a multifactor app for mobile devices.
Firebase - Firebase is a cloud service designed to power real-time, collaborative applications for mobile and web.
andOTP - andOTP is a two-factor authentication App for Android 4.4+
AWS Amplify - JavaScript library for app development using cloud services
Microsoft Authenticator - One app to quickly and securely verify your identity online, for all of your accounts.