unit01
Android
Android 10 or newer
- format
- APK
- size
- 0.7 MB
- SHA-256
- ce4b3176aabf6c7f
Version 1.6 · in development
Text becomes sound. Sound becomes text again.
TWTS sends messages as sound, from one phone or computer to another: through the air, through a cable, or over a radio. It needs no internet, no account and no phone number.
TWTS文 ⇄ 音signal · TWTS
cipherAES-256
servers0
languages11
Morse2800 Hz
signature 7D41 8500 1220 67A5
No network at all
Sound is the only way out. The apps have no internet access: nothing goes to a server, because there is none.
Your own key
Messages are encrypted with a key you hand over face to face, as words or as a QR code. Without it, what is heard is only noise.
Air, cable or radio
Phone to phone across a room, through a computer's sound card, or over a two-way radio.
Text, pictures and Morse
Any language and script, small pictures and drawings, and Morse code that a radio operator can read by ear.
01
Download
Version 1.6 · October 27, 2026unit02
Windows
Windows 10 or 11, 64-bit
- format
- EXE
- size
- 111 MB
- SHA-256
- d998da68f330351e
unit03
Linux · Ubuntu, Mint, Debian
Installs like any program (.deb)
- format
- DEB
- size
- 99 MB
- SHA-256
- 8fede92e70c381e4
unit04
Linux · any distribution
A single file, nothing to install (AppImage)
- format
- APPIMAGE
- size
- 127 MB
- SHA-256
- 42c29552a85a1261
Use the same version on every device: a newer version may send what an older one cannot read.
Earlier versions
- Version 1.5 · October 26, 2026: TWTS-1.5.apk · TWTS-1.5.0.exe · TWTS-1.5.0.deb · TWTS-1.5.0.AppImage
02
How to install
Android
- Download the file on the phone and open it.
- Android asks to allow installing apps from this source (the browser or Files): allow it.
- Tap Install. To update later, install the new file over the old one: the conversation and the keys stay.
Windows
- Download the installer and open it.
- Windows shows “Windows protected your PC”, because the installer is not signed with a paid certificate. Click “More info”, then “Run anyway”.
- Choose where to install it and finish. TWTS opens from the Start menu.
Linux · Ubuntu, Mint, Debian
- Download the .deb file and double-click it.
- The software installer opens: click Install and type your password.
- TWTS opens from the applications menu. In a terminal, instead:
sudo apt install ./TWTS-1.6.0.deb
Linux · any distribution
- Download the AppImage file.
- Right-click it, open Properties → Permissions and allow running it as a program. In a terminal, instead:
chmod +x TWTS-1.6.0.AppImage - Double-click it to open TWTS. To have it in the applications menu, turn on Settings → “Show TWTS in the applications menu”.
On Ubuntu 24.04 and newer the AppImage may not start: use the .deb there.
On Linux, TWTS keeps its device key in the system's keyring (GNOME Keyring or KWallet), which most desktops have. Without one, TWTS warns you each time it opens.
03
Security
spec sheet- cipher
- AES-256, with a key you hand over face to face, as words or as a QR code.
- Network
- None. The apps have no internet access: nothing goes to a server, because there is none.
- Storage
- Sealed by the device's own key: the Keystore on Android, the system's keyring on a computer.
- Audit
- There has been no independent audit yet. If your safety depends on TWTS, write to us first: twts@nexflint.com
Check your copy
Take TWTS only from this site or from someone you trust. To check that a file is the genuine one, compare its SHA-256 with the one listed here.
| TWTS-1.6.apk | ce4b3176aabf6c7f559eaf0bf7acf98035ca50fb8ef0eabd4e578d45d778599e |
| TWTS-1.6.0.exe | d998da68f330351e2ab0fc3fb42d1afc4a10917a272957eab713c08a548ab2ae |
| TWTS-1.6.0.deb | 8fede92e70c381e4e57ed39c0390f21884afbc8108ff83912a39b7d5fc34d389 |
| TWTS-1.6.0.AppImage | 42c29552a85a12617ad4cd27db157f20de2588f3f3357aa00320a38c405f903d |
| TWTS-1.5.apk | 3a5d8e0806be4d724b95ae3f71e12577aa0d4d3cb50b4ae68ec1b4a4827bfa04 |
| TWTS-1.5.0.exe | 19d4e0ba82c147d94f2336339e0b07a82db3fdb424aadef5aace31b1732ecf58 |
| TWTS-1.5.0.deb | ef26cd4688d92a64e3ef4e169f4002e9d927d76c7e9b68c6da5f9e4c9e572076 |
| TWTS-1.5.0.AppImage | a664663c862ab11482cab0e1c9cfacc2dfcf63dd24b88dd9fc6c7c241482f628 |
On Linux:
sha256sum TWTS-1.6.0.AppImageOn Windows (PowerShell):
Get-FileHash .\TWTS-1.6.0.exe -Algorithm SHA256On Android, once TWTS is installed, “State and log” → “App signature (SHA-256)” must show:
7D:41:85:00:12:20:67:A5:7B:AB:66:2B:12:F9:52:6E:02:33:1E:1E:F7:2B:4C:98:C5:7D:B1:B9:68:10:BF:BC04
Contact
Questions, problems, ideas, or a security issue to report:
twts@nexflint.com