We designed the Chirp Messenger solely as a simple app to highlight the benefits of Chirp SDKs. Because of this, we've put the code on GitHub so you can make your own and see how the Chirp SDK works.
These examples all require the Chirp SDK which is available here
Chirp enables data to be transferred via sound, using a device’s existing speaker and microphone. It can use audible or ultrasonic frequencies, works in the most challenging acoustic environments.
As the interaction takes place entirely through sound, it requires no network connection or specialist hardware, just a simple speaker and microphone.