Authy is a simple way to manage two-factor authentication accounts. Authy supports Gmail, Dropbox, LastPass and thousands of other sites.
It implements Time-based One-time Passwords (TOTP) and HMAC-Based One-Time Passwords (HOTP). Simply scan the QR code and login with the generated 6-digit code.
Unmaintained, see https://github.com/andOTP/andOTP and developers announcement on XDA https://forum.xda-developers.com/t/app-4-4-open-source-andotp-open-source-two-factor-authentication-for-android.3636993/post-87021655
FreeOTP+ is a fork of FreeOTP with an updated user interface and with backup/restore functionality (to external files or via built-in Android backup/restore).
Twilio is a web-service API that lets you use your existing web languages and skills to build voice and SMS applications. We focus on building a simple, powerful, pay-as-you-go communications platform so that you can focus on what you do best.
Authenticator generates secure 2 step verification tokens on your device. It help’s you protect your accounts even more.
SAWO is an authentication solution which helps websites and apps onboard user without passwords and OTPs thus reducing bounce rate and increasing conversion.
LibreOTP is an open source two-factor authentication web application for systems utilizing one-time password protocols.
nOTP is an innovative product that allows you to authenticate and verify users without any actions from their end. Available as an SDK currently for Android phones, it works much faster than the typical OTP verification.This app doesn't have any features at the moment.