Tone Cards
No app to download, no account, no Wi-Fi needed. Open this page on your phone — one person types a message, everyone else nearby just listens, and it appears on their screens at the same time.
On stage
Encodes your text using ggwave and plays it through your speaker.
How the encoding works
Your text (with a one-character prefix flag if it starts with a known shortened-URL domain) is handed to ggwave, which encodes it as multi-tone FSK audio protected by Reed-Solomon error-correction codes — meaning the receiver can recover the original message even if a few tones get corrupted by noise, echo, or interference, rather than requiring a perfect run like our earlier hand-rolled version did.
In the crowd
Uses your microphone and ggwave's decoder to listen for and decode the signal, locally, on this device.