Pranav Dixit, writing for BuzzFeed News: Google's goal for the brand-new payments app it launched in India on Monday is simple yet ambitious: to get in on the action each time someone sends or receives money in its largest market outside the United States. The app is called Tez -- Hindi for "fast" -- and it lets users do three things: send money to people in their phones' address books, make payments to businesses (both online as well as in real-world mom-and-pop stores), and zap cash to anyone around them -- all without knowing bank account numbers or personal details. Tez is powered by UPI, short for Unified Payments Interface, a Indian government-backed payments standard that lets users transfer money directly into each other's bank accounts using just their mobile numbers, or a bank-issued payment ID that looks like an email address. It works a lot like Venmo does in the US, except that anyone can build their own payments app on top of UPI. Once you hit Pay or Receive, Tez detects other Tez users around you with a proprietary technology called Audio QR based on ultrasound, and pairs with their phones. Once a sender puts in the amount and authenticates with a preset PIN to confirm who they're sending money to, a transaction happens in seconds.