Every cafe near me uses an iPad point of sale. Can I run yours on the iPad I already own?

Not the counter app today. The app you can download is Android, so a POS that sells, a kitchen screen or a waiter's phone needs an Android device. Your iPad is still useful: the whole dashboard and your ordering page work in its browser, so you can manage the menu, watch the orders board and read reports from it. An Android tablet costs a fraction of an iPad, and the app needs nothing special from it. If an iPad point of sale is the one thing you cannot give up, this is the honest answer rather than a maybe. The POS and the counter tab in the docs says which devices work.