Clef provides easy-to-use strong two-factor authentication using smartphones.
https://wordpress.org/plugins/wpclef/
Widgets · WordPress Plugins
Get access to data on 275,861 websites that are Clef Two-Factor Authentication Customers. We know of 30,769 live websites using Clef Two-Factor Authentication and an additional 245,092 sites that used Clef Two-Factor Authentication historically and 16,587 websites in the United States.
Get a list of 275,861 websites using Clef Two-Factor Authentication which includes location information, hosting data, contact details, 30,769 currently live websites and an additional 3,831 domains that redirect to sites in this list. 245,092 sites that used this technology previously and 16,587 websites in the United States currently using Clef Two-Factor Authentication.