The wallets actually do a lot more than that. Besides vibrating when your bank account makes a transaction, they will make it harder to open when money is tight

The wallets actually do a lot more than that. Besides vibrating when your bank account makes a transaction, they will make it harder to open when money is tight, expand and shrink when you have more or less money respectively. It's about being intuitive and using metaphors to create "Proverbial wallets that allow it's user to experience a financial sixth sense".