Try it the way your customers will.
This is a pretend coffee shop. Join on the phone, then play the cashier: add stamps, hand out the free drink and send a wallet message. Nothing is saved or sent anywhere.
Juniper & Bean
Coffee, pastries and good mornings on Union Ave.
Mon–Sat 6:30am–4pm · Sun 7am–2pm
12 Union Ave (a pretend shop)
The customer's phone