Square's free Mobile Card Reader plugs into the headphone jack of an iPhone, iPad, or Android device.

ENGADGET: Square launches in Canada, streamlines payments on the world stage

Square's Mobile Card Reader is available for free on www.square.ca.

ENGADGET: Square launches in Canada, streamlines payments on the world stage

The best design for a mobile credit-card reader is to embed the encryption function into the actual magnetic stripe hardware.

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They plug in the SquareUp credit card reader into their mobile devices and they can magically accept credit card payment.

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Intuit Inc. (Nasdaq: INTU) today announced that it plans to take its free GoPayment mobile credit card app and card reader hardware global, with the first implementation in Canada.

ENGADGET: Intuit GoPayment's got a brand new card reader for its trip to Canada (Update: hands-on pictures!)

In the US, it has already brought out a similar device, a dongle that can be plugged into a mobile phone to act as a credit card reader.

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Fitted with a card reader, tablets can serve as mobile point-of-sale terminals.

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Flint allows mobile devices to accept credit cards without the need for a card reader or additional hardware.

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GoPayments, PayPal Here or Square Card Reader payment applications that come with credit- and debit-card readers for mobile devices.

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Mobile credit card company Square is making it easier for buyers and sellers to make everyday transactions with its card reader.

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