Before the vaunted NFC option arrives on mobile devices, start-up Naratte hopes to roll out payments that go ultrasonic. Rafe Needleman reviews mobile apps and products for fun, and picks startups ...

The sound wave payment system was introduced with the Alipay Wallet mobile app in January and uses white noise (link via Google Translate) generated by a smartphone to carry digital information to ...

Every smartphone coincidentally has sound-based communication built right in, and that’s the key to how AquaApp, a new app for communicating ... But just like sound waves can be obstructed ...