No internet. No router. No laptop. Still connected.
JoinComms lets Android phones pass text and live push-to-talk voice straight to each other over Bluetooth. There is no server at all. Every phone that joins also helps carry the message further.
Download JoinComms for AndroidWhat it is for
A teacher and students in a village, a field session, or a quick meeting can talk and chat with nothing but their phones. The teacher holds the big button to teach. A student holds it to ask a question. Nearby phones also carry chat messages and short announcements.
How to use it
- Everyone installs the app. Share the file from phone to phone if some people have no data.
- Type your name and tap Start mesh. The top of the screen shows how many phones are nearby.
- Hold HOLD TO TALK to speak. Let go to listen. Or type a message and tap Send.
- Need more reach? Put another phone in between. Each added phone passes messages along.
Which one should I use?
| JoinComms | Wi-Fi Rooms | |
|---|---|---|
| You need | Android phones only | One Mac or Windows laptop; phones join in the browser |
| Carries | Text and push-to-talk voice | Live voice, slides, chat, raised hands, quizzes |
| Reach | About 30 to 50 metres per phone; a chain of phones goes further | The range of the Wi-Fi or hotspot |
| Best when | Nothing else is available: no laptop, no router | A class in one room, with slides and quizzes |
They work well together. Wi-Fi Rooms carries the richer lesson. JoinComms keeps people reachable when nothing else is.
Install in 4 steps
- Tap Download above, then open the file when it finishes.
- If Android asks, allow installs from this source. This is the "Install unknown apps" setting for your browser or Files app.
- If Google Play Protect warns you, tap More details, then Install anyway. The app is shared from our own site, not from the Play Store.
- Open JoinComms and say yes to Nearby devices (Bluetooth), Microphone and Notifications. On Android 11 or older, also allow Location, because Android needs it for Bluetooth searching. JoinComms does not use your location.
While the mesh is on, a small notification stays on screen. This keeps JoinComms running when the screen is off.
Honest limits
- Not encrypted yet. Do not send passwords or private information.
- Android only for now (Android 6.0 or newer, with Bluetooth).
- Short range. About 30 to 50 metres from one phone to the next. A wide area needs a chain of phones.
- Text travels up to 8 phones away. Voice travels up to 4.
- Each phone connects to up to 6 nearby phones at a time.
- Messages are short (up to 300 characters). Voice is plain walkie-talkie quality, on purpose, so it stays light on low-spec phones.
Check your download
To be sure the file is exactly ours, compare this fingerprint (SHA-256) with the one your phone or computer shows.
Show file details
File: JoinComms.apk · 4,085,291 bytes
SHA-256:
f82d828bee98591f741694e0a28d4e0a53e7aa8719a77b8c1b02346c9722eef0