We keep almost nothing, so there’s almost nothing to tell.

Effective October 2, 2026

Wrenword (“Family call check”) helps family members confirm it’s really them on a phone call. It’s free, has no ads, and is built to know as little about you as possible. This page explains exactly what leaves your phone, which is very little.

What stays on your phone

These are created and kept only on your phone, encrypted and locked behind your phone’s own screen lock. They are never sent to us or anyone else:

the people you’ve paired with and the names you gave them;
your rotating words, challenge answers, and duress phrases;
your memory questions and their answers;
your settings, and the history of family alerts you’ve received.

The camera is used only to scan another phone’s pairing code. Pictures are read in memory and never saved or sent.

Phone state. If you turn on the optional “Verify this caller” reminder, Wrenword learns only that your phone is ringing. It never sees who is calling, never reads your call log or contacts, never answers or records calls, and sends nothing about your calls anywhere.

Wrenword has no accounts, and contains no analytics, advertising, or crash-reporting software.

What leaves your phone: family alerts only

Family alerts are optional and off until you turn them on. When you do, your phone talks to Wrenword’s relay, a small server run by the Wrenword developer on Google Cloud. It sends:

A random device ID created by the app, and your phone’spublic key. These let the relay check that requests really come from your phone. They don’t identify you.
A Firebase installation ID. Google’s Firebase Cloud Messaging uses it to deliver alerts to your phone.
Group member lists, as lists of device IDs.
Alerts. Each one is end-to-end encrypted on your phone. Only your family’s phones can open it; the relay passes it along and can’t read it.

The relay stores device registrations (device ID, public key, Firebase installation ID, and the times they were created and updated) and group member lists. It does not store names, phone numbers, or the contents of alerts. Short-lived records it uses to block replayed and excessive requests expire automatically within a day. Its logs contain only hashed device IDs, never the content of requests.

Google provides the hosting (Cloud Run and Firestore) and push delivery (Firebase Cloud Messaging) as a service provider. We don’t sell or share data with anyone else, and we don’t use it for advertising or profiling. All connections use HTTPS, and Wrenword refuses unencrypted connections.

Backups

Wrenword turns off Android’s cloud backup and device-to-device transfer for its data. If you lose your phone, your pairs are gone, and you pair again in person. That’s on purpose: there’s no copy anywhere to steal.

Deleting your data

On your phone: unpair someone to delete everything about that pair, or uninstall Wrenword to delete everything.
On the relay: leaving a family group removes you from it. To delete your phone’s registration entirely, email us. We’ll delete it within 30 days. Step by step: delete your data.

Children

Wrenword is meant to be set up by adults and isn’t directed at children under 13.

Changes

If this policy changes, we’ll update this page and its date. If the app ever starts sending anything new, this page will say so first.

Contact

Questions or deletion requests: use the contact email on Wrenword’s Google Play listing.