Square has opened pre-orders for the next version of its credit card reader. The new device, an update on Square's existing model that could take payment on mobile devices if a customer swiped their card, adds support for EMV credit cards as their use increases across the US. The new reader takes both older magnetic stripe and more modern chip cards; works with iPhone, iPad, and Android devices; and is "small enough to fit in a pocket."

Commonly called "Chip-and-PIN" cards in the UK and Ireland, EMV cards don't require the owner to sign their name — instead they type their PIN into a dedicated terminal. Jesse Dorogusker, head of hardware at Square, says such terminals are "cumbersome, power-hungry" devices that costs hundreds of dollars and require sellers agree to complicated contracts. Dorogusker says Square's Reader is a smaller, more secure — and at $29, cheaper — alternative for those who need to take payment from the newer cards.

The company has also opened pre-orders for an accessory that allows its iPad Stand to accept chip cards. The $39 product connects to the Stand, a white plastic cradle that can act as a point-of-sale register, via USB. Square says it will start delivering the chip accessory in early 2015.

Square pulled its Wallet service earlier this year and cancelled a planned credit card before launch, but its Reader has been the company's most successful product. The new devices enable Square to keep up with the changing ways customers pay for their items, but by only giving the company a small percentage of transactions made with the device, this doesn't necessarily give the company a large amount of money. Once set for a monster IPO, Square has struggled to find a serious revenue source, with CEO Jack Dorsey saying earlier this year that Square was not yet profitable. By adapting quickly to new EMV cards and honing the easy-to-use Square Cash, the company might be able to reverse that fortune.