Multifactor Authentication increases security for your logins by requiring you to prove that you not only know your password, but also that you possess a piece of hardware (typically your phone or tablet).
Userify's MFA requires you to provide a freshly generated code from your TOTP generator on your phone (such as the free Google Authenticator or open source FreeOTP apps for Android, IOS, and Windows Phone) on new web browsers or when you haven't logged in for more than three days.
To enable MFA, simply click Setup MFA in your user profile screen and take a picture of the QR code that's displayed with your app.
You'll also get the MFA badge in project listings. Score!