It's very interesting observing people use the app in person, as opposed to privately on their phone where you have no idea how they interact with it.

For instance the Stripe Terminal reader is immediately to the right of the iPad POS, but a good number of people don't know where to tap the card. I need to design an arrow on the checkout screen for that because I've seen many people tapping the card to the iPad screen. I think Square got them used to that.

It's 2023 but I still think a lot of iPad based POS have a poor ending transaction UX. It needs to be a cute, super clear and simple "All done! Turn the screen around." It's jarring to sometimes be dumped at the item selection menu that is meant for the cashier. Or it just says "Thanks!" without a direction to put the screen back how it was.