is that rapid numeric keying is not what this rotary dial numpad keyboard is all about. In fact, it’s actually an April Fool’s prank [Squidgeefish] played on a retro-phone-obsessed coworker ...

A standard phone keypad consisting of the numbers from 0 to 9 and including the signs "*" and "#". Alphanumeric keypads are an upgrade to those and are used to enter text as well as numbers.

A few things stand out about [Vijay]’s braille keypad for smartphones ... sitting on the back of the smartphone such that you hold the phone much as you often normally would.