Twitter two-factor authentication via 2FA apps and hardware tokens

With over 145 million active users Twitter is widely used not only for personal entertainment but for business and political agendas too. Yet, surprisingly (or not, considering that they did admit to using phone numbers for targeting ads) Twitter has been reluctant to forgo SMS to deliver one time passwords for their 2 step verification for a very, very long time. Until finally, in November last year, they gave in and allowed for Twitter two-factor authentication without requiring the phone number.