Founder of Halocard here.
Okay I am trying out Halocard right now. What the actual fuck, it sends the verification code via Whatsapp to the phone number I provide.
SMS verification is no longer required to sign-up. You can (optionally) verify your phone after you create your account and we'll send the code via whatsapp first and then SMS as a fall-back. This is intentional to combat SMS-pumping attacks we've experienced in the past.