This uses Clef (https://getclef.com/ - which was featured on Product Hunt itself a whopping 2 years ago). Clef lets you use your phone to log into sites securely, and Waltz is a magical Chrome plugin that uses Clef to allow you to login to Facebook, Twitter, etc.

Waltz is great. It allows you to log in to sites with your phone (instead of having to type in your password).

DIdn't get the idea, How Waltz works ?

So... you have to use two devices now? I'd rather use a password manager app than fumble with my phone all the time.