it is easy to customize and works good. Although it is free, they even offer a good support. A minor down side is that after an update you have to reload your language file, but thats ok.
Twilio Login Addon
With the help of Twilio, two-step authentication can add an extra layer of security to your website. Using this add-on, you can connect your Twilio account with the Pie Register plugin to add two-factor authentication to your website and ensure a secure login process. It helps you authenticate the user by sending a PIN to their number, which is required at the login time. Also, admins can be notified when a new user registers.
- Two-step authentication field on the registration form for a user to enter their cell phone number to get a pin number.
- Enter Pin Expire Time in minutes.
- Receive a notification when a user registers.
- Enter Admin Mobile Number to receive registration notifications.