Scan a cup out. Scan a cup back in.
Once you download the app, you can borrow cups at your leisure, at no cost to you (except, of course, if you dont return the cup). Borrow as many as you like, just make sure to return the cups within 21 days.
The app will give you a personal unique q-code that will keep track of your coffee cup usage.
The store will have a 2 different scanners to sign in and sign out cups.