If you’re a regular at a coffee shop or some other small business that uses Square’s checkout system, you’ve seen the same gray-and-white screens — tip, signature, receipt — over and over and over. But today, Square is opening up the ability for developers to create brand-new interfaces for Square’s payment system to be attached to so that businesses don’t all have to use the exact same app.

That means, eventually, your local coffee shop could end up with a colorful interface, new options, and a totally different layout. They can customize the experience so that it makes more sense for their business, potentially streamlining or adding additional options to the checkout process.

Shake Shack already made a custom Square interface

The possibilities are actually much broader than that. The toolkit that Square is opening up will allow companies to create completely new experiences hooked up to Square’s payment system. Shake Shack, for example, got early access to this toolkit and used it to build a complete self-service kiosk that allows customers to go through screen by screen to place an order and check out. That was never possible in Square’s app, which requires a cashier to ring in every order.

Companies could also create new interfaces that are just meant for their own employees. So, for instance, if a restaurant wanted to create a table management system from scratch that relied on Square for payments — instead of, say, using Square’s own table management system — they could do that. Square is also hoping this will allow its payments processing service to end up in far more specialized and niche industries, where its app never would have been able to cut it.

Square hardware is still required

Square says that, for security reasons, businesses will still be required to use some kind of Square hardware for reading credit cards. The software and hardware are also supposed to ensure that only Square ever sees a customer’s credit card data, despite the payment system living inside of a third-party app. But the hardware can be as simple as a Square card reader, with the app running on whichever iOS or Android device a business prefers.

At this point, Square finds itself competing with other payment platforms in a much more direct way since it’s competing to run entire systems, rather than just offer a simple option for businesses to get up and running. Square says it’ll compete on security, integration with features like loyalty programs, and, of course, card fees, which is where Square will continue to make its money. (It won’t cost companies anything extra to build their own system.) Whether or not Square is actually the cheapest option may depend on the type of business, as other payment processors offer different fee structures that may better fit companies selling at certain price points or quantities.

For consumers, though, the big deal is that checkout interfaces could change — for better or worse — thanks to this new toolkit. And after making a purchase through some unfamiliar interface, you could end up with an emailed receipt from Square without even realizing it was a Square system you paid through.