WaveIt is a suite of applications on Android and Web that allows for the transfer of data via Sound Wave technology. It is comparable to QR codes, but using Sound Waves.
To send a Wave, simply upload the text, files, or images you want to send, and click "Send Wave". This will play a short Sound Wave which another device can listen for.
To listen for a Wave, simply press the "Listen for Waves" button and then have a Wave play from another device. Your device will detect the Wave and display a popup allowing you to download or discard the text, files, or images contained in the Wave.
WaveIt was first created as a hackathon project at Hack the 6ix, and now it has been developed to a full app.
Updated how the application sends requests and added support for Android 4.4 KitKat.