Square Register Socket 7CI Bluetooth Cordless Hand Scanner (CHS), Socket Mobile CHS 7CI Cordless Barcode Scanner, 1D Imager, Includes Socket CHS 7CI Barcode Scanner, Two AAA NiMH Rechargeable Batteries, USB AC Charging Kit, Lanyard/Belt Clip with Retractable Tether, Dark Gray Color – CX2870-1409
NOT FOR USE WITH SQUARE STAND! If using a Square Stand consider the Square Stand Starter kit which has a printer that plugs into the stand. The printer in this kit must be plugged into your router.    
We recommend using the Square contactless and chip reader for a fast, seamless payment experience on all devices – not just those without a headphone jack. To accept magstripe-only cards, or gift cards, we recommend using the Apple Lightning to Headphone Jack adapter (included with the iPhone 7) to connect your Square magstripe reader. You might also try a third party USB-C to 3.5mm audio adapter, but please note that Square has not officially tested compatibility between the magstripe reader and other third party adapters.
Atm it’s cheaper for me to use something else other than square, than to change the printer tablet setup. It appears other people have similar issues. Square managment need to grasp the economics here of only catering to a small hardware segment(Star printers) of the market, while marketing themselves as a simple DIY eftpos POS for small businesses, who burn themselves on compatability issues. Hopefully Square can solve this issue.
Square Register Star TSP100III Thermal Receipt Printer with Auto-Cut, Ethernet Interface 10/100BaseT (LAN), Internal Power Supply, Includes TSP143IIILAN, Power Cable, Ethernet Interface Cable, Mounting Kit, Paper Roll, Dark Grey Color – TSP143IIILAN GY US – 39464910
@SSmobile @Kevin7 – I went ahead and moved both of your comments over to the thread where we are tracking this feature request. I totally understand your frustration and desire for Epson support. They make a mean printer that is also a fraction of the cost of most Star printers. I have personally passed this feedback along to our product team, and expanding compatibility is something that is top of mind for them. I’ll update this thread if/when this functionality is added in the future! 
When you connect to the USB Receipt Printer or Ethernet Receipt Printer with the included cable, the cash drawer will open every time you complete a cash sale. Or use the included keys to manually open.

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An update 11/21/15 Had it working fine with Amazon local register until Amazon shut it down, so bought the PayPal chip and card reader- the updated paypal iOs app will not print to this printer. (iOs 9.1/ iPad 3). The workaround I found was to turn this printer in to an airprint printer- it’s a bit of a hack, instructions are out there, problem being you must have a host computer on the network. To be clear- this is a PayPal issue- not a fault of the printer.
A simple print button on the tablet application would allow us to connect to a local or network printer and print the same form data. Why is this still impossible? Why can we still not utilize our desktop or local printers to print receipt data from the app? 
Most receipt printers I have seen use a wired ethernet connection, so you could add a slick Lantronix xPrintServer which uses AirPrint to avoid needing a computer running for your iOS devices to print to these specialized printers.
Star Micronics TSP100GT Fast, reliable thermal printing is a snap with the Star Micronics TSP100GT. This printer offers additional configuraiton, including embedded graphics and logos, adding flair to retail receipts. The TSP100GT supports iPhones as well, giving you an option for receipt printing with your mobile POS installation.
Cash Drawer   Features: This cash drawer box is made from robust steel. Comes with RJ11 cable, plug for connection to receipt printers. Standard-duty, fast and reliable cash drawer. The 3-position …
Implementing Bluetooth printing introduced new limitations in parallel processing and communication that required me to rethink how we manage concurrency in our printing system. If you’re familiar with multi-threaded code, you probably already realize that expensive operations, such as peripheral communication, downloading and uploading, and heavy computation, are best run asynchronously off the main UI thread. In our code for WiFi printing, this is done using the most basic functionality of Grand Central Dispatch (GCD), one of Apple’s built-in mechanisms for managing concurrent tasks. For more detailed info about GCD, read Apple’s documentation . Each print operation and printer discovery operation is added to a global concurrent queue that runs the code on a private thread, abstracting away the mechanics of threading. The result of this is that the different operations are allowed to run in parallel with no restraints and no control.
58mm POS Printer 384 line Thermal Dot Receipt 12v USB Printer Set w/ Roll Paper Package Content: 1 x Thermal Printer 1 x Instruction Manual 1 x Printer Driver 1 x USB Cable 1 x Power Cord 1 x 58mm The…
Receipt Printer Compatible With Square, A cash drawer needs to be linked to an invoice printer to open immediately. Otherwise, you’ll have to buy hand open the drawer utilizing the money drawer secret. * This standard money drawer is not able to link to an invoice printer.
The new Square Contactless and Chip Reader is included so you can accept every way your customers want to pay. Place the reader in the dock, connect the dock to the USB hub, and you’re ready for business. Accept magstripe cards, chip cards, and NFC payments like Apple Pay.
The STAR MICRONICS SM-T300I is also a light weight receipt printer. But it’s very durable and rugged. It’s also Apple MFi certified for iOS phone and iPads. It also works with Android and Windows. It’s been tested to take a little bit of beating and is used by people who are outside a lot. Having said that the price is higher than other printers. If you need something rugged, this device may be the one for you. But if you don’t. You will want to look at something else as this device can get expensive. The SM-T300i is easy to use. There is a well written and very detailed user manual. The user manual gives details on how to configure the receipt printer and how to load paper. Here is a link to the Star Micronics SM-T300i User Manual.
Barcode PrinteriPad Point of SaleBarcode ScanneriPad Barcode ScannersCash DraweriPad Cash DrawersCredit Card ReaderiPad Receipt PrintersGift Card PrintingiPad POS StandsMobile ComputeriPad POS KitsPOS SoftwareiPad POS Apps
Print 58mm wide thermal paper, with 100km reliability TPH life. Paper Width: 58mm( -0.1mm). POS-5805DD mini thermal printer is compatible for iOS Android Windows devices, supporting BT(wireless), USB …
Connect your Square Stand with a compatible iPad and recommended hardware accessories to help run your business. Before purchasing a Square Stand, make sure you’re using a supported iPad. You can identify your iPad model on Apple’s Support site.
Complete your countertop POS system with this Square register kit. Print paper receipts, daily sales reports and summaries right from your iPad. Includes, Square reader, Star Ethernet Printer, APG 13″ Vasario Cash Drawer, drawer cable, extra 2 rolls of thermal receipt paper and installation support. 
Square introduces more ways to engage with customers. Square now integrates with cash drawers and receipt printers. With a single tap on an iPad, you can open your register’s drawer to complete a cash sale or make change. Please read the options below carefully before purchasing a cash drawer.
It has 5 bill trays, 5 coin trays and a bill entry, keeping your money organized and largely improve your working efficiency and accuracy. Electronic Cash Drawer There are 5 bill trays and 5 coin tray…
I don’t have any personal use of this but this item says it takes usb input and converts it to the connection that would come out of the printer from what I understand.  It may work, it may not.  There are no reviews that are helpful of the product.
I started off the implementation of Bluetooth printer support by using the same concurrency model used by our WiFi printer code and running Bluetooth printing and printer discovery blocks on a global concurrent queue. I quickly found what appeared to be a non-deterministic bug — sometimes I could print a receipt with no problem, and other times it would fail part way through. What I was in fact encountering was a timer firing and searching for connected printers while the app was in the middle of sending data to a printer. While this behavior was perfectly acceptable in communication for WiFi printers (TCP supports multiple simultaneous connections), it totally broke down in the new communication channel. It became clear that some kind of mutual exclusion was necessary to prevent this kind of collision.
Make sure not to send your customers’ receipts to yourself. You’ll receive a payment confirmation after every successful transaction, and you can view payment details from your online Square Dashboard.
Square systems are primarily compatible with Ethernet or Bluetooth interface printers (depending on the tablet you are using, Android tablets with USB ports and USB On-The-Go or USB Host mode can use USB interface printers). The compatible printers for Square systems are as follows:
Mini Bluetooth Printer is a portable thermal printer that combines USB, RS-232 Serial and Bluetooth communication interface together. Support IOS Android. It can print 58mm width thermal paper. Ther…
IOS operation system test (APP: blue light). Mini Bluetooth Printer is a portable thermal printer that combines USB, RS-232 Serial and Bluetooth communication interface together. In“Printer-X”will sea…
For future reference, the price is $149.95: store.lantronix.com/product_p/xps1001ne-01.htm (It’s not listed on the page that is linked to, so it took me a while to get what you guys were talking about.) – Mathias Bynens Mar 23 ’12 at 17:21
As a bluetooth only device, it is a bit glitchy. If you are wanting to use it with a phone/tablet only as a standalone device, look elsewhere. The miura m010 reader works great for this, though is unfortunately not available on amazon.
SM-T300i Mobile Printer (SM-T300I2-DB50 US GRY), 3-Inch Print Width, Bluetooth 2.0, Serial Interface, (Includes Serial Cable, Battery Pack, AC Charger, Sample Paper Roll), Color: Gray (Part Number: 39634010)