Square Cardreader
Year First Appeared
2009
Creator
Jack Dorsey, Jim McKelvey
A small, portable Square card reader that works with the Square POS app to take in‑person payments on a phone or tablet. Depending on the model, it plugs in or connects via Bluetooth to accept magstripe swipes as well as chip and contactless payments like Apple Pay and Google Pay.
Importance in Internet Culture
Square’s reader democratized card acceptance for micro‑merchants, accelerating the shift to mobile, software‑defined payments and normalising tap‑to‑pay in everyday commerce. Its rapid early growth – millions of sellers and billions in transaction volume within a few years – showed how a phone plus an app could disrupt entrenched payments infrastructure.
Interesting Fact
The original Square magstripe reader used the phone’s 3.5 mm audio jack as a passive analog interface, feeding the swipe‑induced voltage into the microphone channel for the app to decode, without any onboard digitisation. The company was almost called “Squirrel, ” with an acorn‑shaped prototype, before Jack Dorsey changed the name after spotting a clash with an existing POS brand.