Description: GetOTP is a free and open source two-factor authentication app for Android, iOS, Windows Phone, Blackberry, and Linux. It can generate time-based one-time passwords compatible with Google Authenticator and similar apps. It's lightweight, easy to use, and doesn't require an account.
Type: software
Pricing: Open Source
Description: Twilio is a cloud communications platform that enables developers to programmatically make and receive phone calls, send and receive text messages, and perform other communication functions using its web service APIs.
Type: software
Pricing: Paid