how we treat your story
Safety & privacy.
Sister Signal is a safety tool first. Every design decision passes through one question: would this be safe if someone took the phone right now?
Five commitments.
Privacy-first design
We collect the minimum needed to serve you. Onboarding works without an email or name.
Optional anonymity
A device identifier is enough to use Sister Signal. Email is only required if you want recovery across devices.
Quick Exit
One tap disguises the app as a calculator. The disguise is convincing on lock screens and during a quick glance.
User-controlled data
Export, delete, or pause any data we hold at any time. No dark patterns, no hidden retention.
No selling, no ads
We do not and will not sell user data. Sister Signal is not ad-supported and has no third-party trackers.
Technical details, plainly.
Local-first sensitive data
Incident logs, journal entries, and decode history are scoped to your account and never shared with other users.
Encryption in transit and at rest
Connections are HTTPS; database storage uses provider-level encryption.
Trusted Circle SMS
Sent via Twilio's Messaging Service with carrier-level STOP handling. The first message each contact receives includes a clear opt-out line.
No location tracking
Approximate location can be optionally attached to a check-in alert. It is never tracked passively.
if you are in immediate danger
Sister Signal is an emotional safety companion, not an emergency service. If you are in immediate danger, please call 911. The National Domestic Violence Hotline is available 24/7 at 1-800-799-7233 (text START to 88788).
For the full legal text, see our Privacy Policy and Terms of Service.
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