The Verge:

To use Square Cash, all you do is compose an email to a friend, type the amount you way to pay in the subject title, and cc cash@square.com. If it’s your first time using the service, you’re directed to Square’s website where you type in your debit card number — and you’re done. There are no accounts to create, apps to download, friends to add, surcharges to pay, or bank account numbers to look up.

That simple.

I wish this was available in France. It would free my group of friends from recurring problems and discussions about money.