Frequently asked questions

Gart runs on Android and comes from Zapstore, an app store that needs no account. Install Zapstore first: download Zapstore and allow your phone to install it. Then open Zapstore, search for "Gart" and tap Install, or open Gart on Zapstore on your phone. Zapstore handles all future updates automatically.

The install guide shows each step.

Not yet. The iPhone version is in development. Apple users can contact us or follow us on X (Twitter), LinkedIn, or Nostr to be notified the moment it launches.

Yes, a Gart account, though not in the usual sense. Other apps ask for an email address and a password. Gart asks for neither, and for no phone number. When you first open Gart, you choose a username and the app generates a cryptographic keypair on your phone.

The public key is your identifier: other Gart users find you and invite you by it. The private key is the part you keep safe. It works like a password and is the only way back into your account on a new phone, so back it up from Settings > Backup as soon as you are in. If you log in with a remote signer app, that app holds your key.

Your account connects you to your circle and keeps your group memberships and history with you across devices.

Gart works without an email address or phone number, so there is no account-recovery email to fall back on if you lose your device. Your access depends on your private key, so back it up from within the app before you ever need it. With the key backed up, install Gart on a new phone and log in with that key or your remote signer. Gart finds your latest app backup and offers to restore it, and your group memberships and history come back with you. The backup steps are explained in our user manual.

A group can include up to 10 Responders. The Group Owner is not counted among them.

The Group Owner creates the group and is the only person who can trigger alerts. A Responder receives alerts and can respond to them. One person can be a Group Owner in their own group and a Responder in other groups at the same time. Roles are per group, not per account.

Search by username or npub directly in the app, or scan their profile QR code to pull up their profile and send an invite in one step. For contacts who don't have Gart yet, you can share an invitation link from Settings or the user search page. The link walks them through installation before they can join.

Share an invitation link from within the app and send it via Signal, email, or any channel you use. The link guides them through installation first.

Yes. The Group Owner can invite new and remove existing Responders.

A Test alert lets you run through the full alert process without triggering a real emergency response. The message and the location are both locked in place: the message reads as a non-emergency notice, and the location always points to a fixed coordinate on Mount Everest. Your real coordinates stay private.

A Live alert broadcasts your current GPS coordinates to the group alongside the message you wrote. Use it only in a genuine emergency.

Test alerts are available from within the group screen. Select the Test alert option, confirm, and hold the button for about 2 seconds. Use Test alerts to verify that every Responder in your group receives alerts reliably before you rely on the real one.

You cannot cancel an alert, but you can stop it. Stopping sends a visible stop notification to all Responders and displays it inside the group.

Responders see your alert message, your current GPS coordinates as text, and an Open in Maps button that launches the coordinates in their device's default maps application.

Responders can tap I'm handling this in response to an active alert. This posts a visible acknowledgment inside the group. The Group Owner and other Responders can see who is actively involved, which prevents confusion when multiple people are coordinating a response.

Yes. Write it before you are in a situation where you need to send it. Open the Live alert message template in the Group information screen and fill in the placeholders with the information your Responders will need most: who to call and what to do. Once a Live alert is sent, the message cannot be edited.

Your location leaves your phone in two cases. A Live alert sends your current GPS coordinates to your group, and while the alert is active Gart sends an update every 15 minutes until you stop it. A check-in (soon) sends your position once, if location is on in your check-in settings; it is on by default.

A Test alert never sends your real position: it always points to a fixed coordinate on Mount Everest. When no alert is active, Gart does not track your location.

Yes. Every message is end-to-end encrypted before it ever leaves your device. Only the members of your group hold the keys to read it. Gart itself cannot.

Only your encrypted app backup. Gart runs no servers for alerts and chat messages: they travel over public Nostr relays that other people run, encrypted before they leave your phone, and only your group can read them. Gart cannot read your messages or access your location.

The one server Gart runs is an encrypted backup server. Every day, when you log out, and whenever you back up by hand in Settings > Backup, the app encrypts a copy of your app data on your phone and uploads it there. The copy holds your groups and their members, your settings, your chat messages, the locations of past alerts and the keys the app uses. Only your own key can decrypt it, so Gart cannot read it. To accept the upload, the server keeps your public key on its list of accounts allowed to store a backup.

When the app crashes, it sends a technical report to the team. The report contains crash data only: no message content, no location. A separate analytics service records anonymous usage patterns to help us improve the app. We collect no personally identifiable information. We are reviewing both services before public release.

No. Gart requires an active internet connection to send and receive alerts. You can use Wi-Fi or mobile data. Sending a Live alert requires an active GPS signal, not a SIM card.

Shake your phone from anywhere in the app the moment you spot an issue. A screenshot is captured automatically. If you'd prefer not to include it, remove it from the Report Issue screen before sending. Add a brief description and tap Send. The report and its technical logs go directly to the team.

You can also reach this form via Settings > Report an Issue.

Send your questions through the contact form and choose "Gart app". For bugs and technical errors, use Shake to Report in the app or Settings > Report an Issue. These capture the technical context the team needs to investigate.

Beta testers also have access to a Signal group for questions and discussion with other testers. Ask for an invite through the contact form.