Features

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Tetracom is a walkie-talkie style messaging app. One tap holds to talk, and your voice goes straight to the person you picked. This page walks through everything the phone app can do, grouped by area. Two topics have their own deep-dive pages — you’ll find links to them in the matching sections below.

On this page

• Where Tetracom runs (app & web)
• Getting started & identities
• Contacts
• Contact groups & Safety Circle
• SOS
• Talk: push-to-talk voice
• Asking with options
• Location & the map
• Notifications & sounds
• Staying connected when locked
• Account & settings

Where Tetracom runs (app & web)

There are two ways to run Tetracom. Both use the same Tetracom server, but the current Web App cannot yet exchange messages with the Android app. Each identity lives on the phone or browser where you registered it (the Web App can export a backup of an identity and import it in another browser).

• Android app — the native client, the fullest experience on Android. Installed from an APK during the prototype (no Play Store listing yet).
• Web App (PWA) — open tetracom.me/app in your browser on any phone, tablet, or computer. Add it to your home screen or desktop and it installs and launches like an app, in its own window. On iPhone and iPad the Web App is the way to use Tetracom today, and you must add it to the Home Screen to receive push alerts (push needs iOS 16.4+).

The features described on this page are written for the app; the Web App covers the same core — push-to-talk voice, text and questions, location and the maps, groups, and SOS (without SOS audio) — through the browser. For step-by-step install on every platform, see the install page.

Getting started & identities

The first time you open Tetracom, you register a userid. A short form asks for four things: your Server URL, a Userid (3 to 30 characters), a Display name, and your Date of birth. Fill them in and tap Register.

Your userid is your permanent handle — it is how other people reach you (for example, alice_e2e). Your display name is just a friendly label your contacts see; it is not how people find you, and you can set a different display name for each identity.

Several identities on one phone

You can keep more than one identity on a single device. Each identity has its own contacts, keys, history, and inbox in the app. Our server can still tell that these identities are on the same phone; see the privacy policy.

Contacts

The Contacts tab is where you manage who you can talk to. Tap the Add a contact button to open a dialog with three choices:

• Add by userid — look someone up by their userid and send them a connection request.
• Invite via SMS — send a text invite to someone who is not on Tetracom yet.
• Redeem code — paste an invite code that someone texted you.

Connection requests

Connections need approval from both sides. When someone wants to connect with you, their request appears in a Pending requests section as a card with Approve and Reject buttons. Requests you have sent appear under My pending requests with a Withdraw button while you wait for the other person to respond.

Online status

A contact who is connected right now shows a green dot and the word online on their detail screen. This is handy before you try to talk to them or ask for their location.

Blocking

To block someone, open the contact and tap Block (the red button). A confirmation explains what happens: Tetracom will silently drop every message that person sends, they are not notified that they were blocked, and they are removed from your contacts. Once blocked, the button changes to Unblock. Unblocking restores delivery, but it does not re-add them to your contacts — you would send a new connection request for that.

Per-contact settings

The contact detail screen also has a few per-person controls:

• A Share my location with this person checkbox (see Location below).
• A button to request that contact’s location, enabled only when they are online.
• A per-contact notification override (see Notifications below).

Contact groups & Safety Circle

A group is a name you give to a set of your contacts — like “Family” or “Climb crew.” Once you have one, you can send to everyone in it with a single tap instead of picking people one at a time, and you can send any kind of message to a group: voice, text, a question with options, or your location.

You build a group on the Contacts tab: open Groups, tap Create group, give it a name, tick the contacts to include (only people you are already connected to), and save. To send to a group, pick it as your recipient just like you would a single contact, then send as usual. Everyone in the group gets their own private copy, and each person replies straight back to you — replies do not go to the whole group.

When someone messages a group that includes you and there are members you are not yet connected to, your app shows a “Join group?” request. If you approve, Tetracom automatically sends a normal connection request to each member you are missing; their app even tells them you are both in the same group, so the prompt reads “X wants to connect — you’re both in group Family” instead of a bare request. As each person approves, everyone ends up connected. If you decline, nothing is saved.

You can also mark one group as your Safety Circle — the people you would want reached in an emergency (only one group at a time). Your Safety Circle is who an SOS reaches.

Full guide: Contact groups & Safety Circle →

SOS

SOS alerts your Safety Circle in an emergency. In the Android app, tap SOS and confirm, and everyone in your circle gets a private, end-to-end-encrypted alert with your location. In the Web App, tapping SOS starts a 5-second countdown you can cancel; when it ends, the alert is sent. The confirm step (Android) or the countdown (Web App) lets you back out of an accidental tap.

You stay in control the whole time: only you can start an SOS (no one can trigger it remotely), the Android app shows an ongoing “SOS active” notification with a Stop SOS button while it runs (the Web App shows a Stop SOS button), and Stop is always one tap away. Your location is shared with the circle only while the SOS is active, then stops. People in your circle can tap Acknowledge to clear the alert on their own screen; you are not told that they did. You get an on-device record of what you sent.

Optional audio evidence (off by default)

Tetracom can also let your Safety Circle hear what is happening during an SOS by sending short audio clips. This is off by default and only ever happens when you turn it on — nobody can listen in remotely. You switch it on with “SOS audio evidence” in Settings, then choose how it is sent when you set up your SOS group:

• Automatic — tick “Record & transmit sound every 15 seconds” in the Contacts SOS-group setup, and an active SOS records and sends 15-second clips on its own.
• Manual (the default) — leave that un-ticked and audio is sent only while you hold the push-to-talk button (the microphone image) or the phone’s Volume Up key, then let go to send.

Recording is completely silent on your phone (no beep or shutter), each clip is end-to-end encrypted to your circle, and it stops the moment you end the SOS.

Full guide: SOS & your Safety Circle →

Talk: push-to-talk voice

The Talk tab is where you speak. Push-to-talk works two ways:

• Press and hold the phone’s Volume Up button, or
• Press and hold the on-screen microphone (Talk) button.

Speak while you hold. The moment you let go, the clip sends automatically. If you keep holding, the recording auto-stops after 30 seconds.

Hearing what people send you

By default, incoming voice plays as soon as it arrives, through the loudspeaker, like a walkie-talkie. You can change this in Settings → Notifications (for example, to a notification sound or silent). Voice messages also appear in your History tab with a play button, so you can replay them.

Transcribe voice to text (not available yet)

The app has a “Transcribe voice messages” setting (off by default) and a Transcribe action on voice rows in History. The current version does not include a speech-to-text engine yet, so these show a placeholder note instead of text. Nothing is sent to any server.

Asking with options

This is how you send text in Tetracom. Instead of a freeform chat message, you send a question with a row of tappable option buttons. The recipient taps one, and their answer comes straight back to you.

Open it with the Text button on the Talk tab. You must have exactly one recipient picked first — otherwise a toast appears reading “Pick exactly one recipient to send text to.”

In short: you can add anywhere from 2 to 32 options, mark a question Urgent, and choose to be notified if the answer changes. There is a lot more to it — the full walkthrough is here:

Full guide: Asking with options →

Location & the map

There are two separate location features, and it helps to keep them apart:

• Sharing your location with a contact — sending where you are to another person.
• Where am I? — a button that just shows you where you are, sending nothing to anyone.

Sharing your location

Sharing is off by default for privacy, and you turn it on in two steps:

While both are on, each time you send that person a voice message the app also sends them your location, as a separate end-to-end-encrypted message, and it automatically answers their location requests (except “Ask every time” requests, which always ask you).

“Ask every time” — decide on each request

If you would rather not share automatically, Tetracom can ask you each time a contact requests your location. When a request comes in you get a prompt: Share once sends a single current location to just that person, or Deny sends nothing. Your location is never shared without you tapping Share once for that specific request.

Full guide: Location requests — Ask every time →

Send your location to several people at once

You do not have to send your location one person at a time. On the Contacts tab you can select several people at once, then tap the send-my-location button — everyone you picked gets your location in a single step. Tetracom confirms what happened: send to one person and it reads “Location sent ✓ to” that contact’s name; send to several and it reads “Location sent ✓ to N recipients.”

Viewing a location you received

Opening a location someone sent you brings up an in-app map (OpenStreetMap) with their pin on it. From there you can tap Open in Google Maps if you want satellite imagery or directions.

See everyone on one map

In the Android app, tap Where am I? on the Talk tab, then the map icon in the map’s header. In the Web App, tap See everyone. Either way, a single map shows the latest location each contact has shared with you, each as a labeled marker.

In the Android app, a few controls sit on that map:

• Filter chips — a row of name chips lets you narrow the map to just the people you care about. Everyone starts selected; tap a name to hide or show that person. Unselect everyone and the map shows no one.
• Show your own position — a toggle in the map header overlays your own spot as a blue You marker, so you can see where everyone is relative to you. It starts on if you have already granted location permission; turn it off to hide yourself.
• Auto-zoom — the map automatically zooms to fit everyone shown (plus you, if shown). You can pan and zoom yourself afterwards.

Tap any person’s marker to see their name, their coordinates, how accurate the fix is, and how long ago it was (for example, “3 min ago”). If nobody is sharing right now — or you have filtered everyone out — the map reads “No one is sharing their location right now.”

Where am I?

The Where am I? button lives on the Talk tab. It opens the in-app map and drops a pin on your own current spot. Your location is not sent to Tetracom or to your contacts. The map pictures come from OpenStreetMap, whose servers see which area you are viewing. If you tap Open in Google Maps, Google receives your position.

Full guide: Where am I? & the map →

Location-based ads

The ad shown in the bottom bar can optionally be matched to your area, and this is off by default. In Settings → Location-based ads you can choose Off (no location is sent for ads, and you only see ads that are not limited to an area), Approximate (your phone’s last known location is rounded to about a kilometer before it is sent), or Precise (your phone’s last known location is sent without rounding). Your location is only sent for ads when you opt in, and you can change this anytime.

Each time an ad is shown or tapped, Tetracom stores a record with your userid and the time. If location-based ads are not Off, the record also holds your location rounded to about a kilometer. These records are kept with no time limit, and turning the setting off does not delete them. See the privacy policy.

Advertisers can choose where each of their ads shows, set right in the advertiser portal on a map: everywhere (the default), within a set distance of a point on the map (drop a pin and enter a radius in kilometers), inside a named region, or a custom area they draw themselves. A Tetracom admin reviews the targeted area — shown on a map — before the ad goes live.

The advertiser portal also shows each advertiser aggregate analytics for their ads — presentations, clicks and click-through rate, an age-band breakdown, and a location heatmap. These figures are aggregate-only: they never identify individual users, and very small groups are hidden for privacy.

Notifications & sounds

The Settings → Notifications screen controls what happens when a message arrives. You pick a behavior (for example: play immediately, play a notification sound, vibrate, or stay silent) and a sound.

Sound choices

There are ten options, and each one has a preview/play button so you can hear it first:

• Walkie squelch
• YYZ in Morse
• Two short beeps
• Sender’s ID in Morse — spells out the sender’s userid.
• Custom text in Morse — type any short text and hear it as Morse.
• Single chime
• Rising arpeggio
• Triple tap
• Pick a file from device — choose any audio file on your phone.
• Record from mic — record a few seconds yourself: pick a duration, tap record, tap stop.

Per-contact override

On any contact’s detail screen, Notification override for this contact lets you give just that one person a different behavior and/or sound, overriding your global default. Useful when you want one contact to always break through.

Audio cues

Also under Notifications, you can add optional short beeps around voice playback and recording. Each is a count from 0 to 3, with a sound you can choose:

• Beeps before voice plays
• Beeps after voice plays
• Beeps before recording starts
• Beeps after recording stops

Staying connected when locked

The Settings → Connection screen has a Stay connected when phone is locked switch. Turning it on places a small, silent, always-on notification in your status bar. That notification is what stops Android from suspending Tetracom while your screen is off or locked. Without it, your phone may stop delivering messages in the background.

Account & settings

Here is a quick rundown of the Settings screens in the app:

• History — choose how many messages are kept per identity. Pick a number (for example 10, 20 (the default), 50, 100, 250, or 500) and Tetracom keeps that many of your most recent messages, dropping the oldest once you go over. You can also set it to 0 (ephemeral): in that mode a message disappears as soon as you have read or played it — voice clips clear once you finish playing them, and text, location, and other messages clear when you leave the History tab after viewing them. Unanswered questions are the exception: they always stay until you answer them (or the sender cancels), so you never lose a question you still need to act on. The new Clear history button is described below.
• Location — the global Send my location with messages switch (see Location).
• Connection — the Stay connected when phone is locked switch (see Staying connected).
• Notifications — behavior, sounds, per-contact overrides, and audio cues (see Notifications).
• Parental controls — link a parent and child together by userid.
• Identities — rename or delete each identity, or add a new one.
• Diagnostics — view the last crash report, and copy or clear it.
• SMS gateway — advanced, and off by default. On a phone that also has the separate Tetracom SMS Gateway app installed, this lets one trusted sender have that phone send a real text message. Most people never need it (see SMS gateway).

Clear history

Under the History setting there is a Clear history button. Tapping it asks you to confirm (“Clear all history? This can’t be undone.”). When you confirm, Tetracom deletes the stored messages for the identity you are using now — voice clips, text messages, shared locations, and questions you have already answered. Unanswered questions are kept, so you do not lose anything you still need to respond to.

Removing an identity

In Settings → Identities, each identity has a Delete identity button. The menu under the account icon at the top of the screen has the same action for the identity you are using now, also called Delete identity. (Older versions of the app call these Remove and Remove this identity.) When you confirm, the app first asks our server to delete the identity, and our server deletes it. Then the app wipes it from this phone — its userid, keys, contacts, and history all go. This cannot be undone. Once our server has deleted the identity, the userid is free and someone else can register it.