Rattlegram

Rattlegram

SMS via audio!

23 ratings
10 reviews
Free

Details

  • Released
  • Updated
  • November 20, 2023
  • January 4, 2026
Rattlegram screenshot #1 for iPhone
Rattlegram screenshot #2 for iPhone
Rattlegram screenshot #3 for iPhone
Rattlegram screenshot #4 for iPhone
Rattlegram screenshot #5 for iPhone
iphone
ipad
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About

This app utilizes advanced COFDM technology for audio-based SMS transmission. It supports various modes with specific encoding and modulation techniques, requiring minimal bandwidth for efficient data transfer.

COFDM technology
Audio-based SMS
160 ms OFDM symbols
Differential PSK modulation
Forward error correction
Low bandwidth requirement
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What's New in Rattlegram

1.10

January 4, 2026

- improved navigation in settings - updated libs and tools

User reviews

Works!

perfect, simple

Texting via HT’s

Allows texting via HT’s when off grid. Easy to operate as well.

Great SMS App

Excellent App. Was able to obtain App for iPad, iPhone, and Android Tablet. All communicated to each other perfectly and easily thru air as well as thru Baofeng UV-5R on VHF/UHF and G-90 on several SW bands. USB is touchy and tuning must be careful, but impossible.

I notice Android version slightly different than iOS version. Found no version for Mac. PC version somewhat difficult to install and requires Android to Windows plugin.

Perhaps greatest App I’ve ran across recently. Thanks!

73s, Tom, ex-WA0DJP
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Favorite radio messaging app

Love this app, I use it with a digirig lite and it works perfect like that. I would also like to see KISS TNC support if possible!

Me encanta

Me he comprado unos cables de audio y conecto los walkis a dos teléfonos para mandar los SMS y me encanta como funciona es una pasada lo bien que descodifica el mensaje que mandas

Response from developer

¡Gracias por tu reseña de 5 estrellas! Nos alegra mucho saber que te encanta cómo Rattlegram descodifica tus mensajes. Agradecemos mucho tus comentarios. ¡Disfruta usando la app!

FAQ

What is Rattlegram's primary function?

Rattlegram's primary function is to transmit SMS messages using audio signals, leveraging COFDM technology for efficient data transfer.

What technology does Rattlegram use for SMS transmission?

Rattlegram utilizes COFDM (coded orthogonal frequency-division multiplexing) technology, which involves specific OFDM symbol lengths, sub-carrier frequencies, and modulation techniques.

Does Rattlegram support different transmission modes?

Yes, Rattlegram currently supports Modes 14, 15, and 16, each with different configurations for systematic polar codes and CRC32C aided SCL decoding.

What is the bandwidth requirement for Rattlegram?

Rattlegram requires a bandwidth of only 1600 Hz, making it efficient for transmitting data with minimal spectral usage.

How fast can Rattlegram transmit data?

With the leading noise and fancy header disabled, Rattlegram can transmit 85, 128, or 170 bytes in approximately one second.

What devices is Rattlegram compatible with?

Rattlegram is compatible with iPhones and iPads.

What is the age rating for Rattlegram?

Rattlegram has an age rating of 4+, making it suitable for a wide range of users.

Does Rattlegram have ads?

No, Rattlegram does not contain advertisements.