The cash card is an intelligent mouse

Wireless, on the table, use it like any other mouse on your computer.

The only thing noticeable is financial applications where the mouse will laser check your palm  and wait for the click code, before you hit submit. And, by the way, you always get the red green indicator regarding any transaction and your risk level. Your mouse is talking to your financial app.

Then take your mouse to the store, point, click, purchase.  ATMs are point click spew paper.  Some kiosks give you a little shelf, put your mouse their and work the tiny ATM screen. Point it at price beacon, get a red/green. Two together will exchange a token safely. Tap it on the screen of your telephones. Complete a real estate deal with them.