Starling 暗号化メッセージ アプリ 向け Android 説明
Starling is private location sharing for your circle: family, a partner, a small group of friends. There is no account to make and no company sitting in the middle reading your position.
End to end encrypted
Your location is encrypted on your device with AES-256-GCM under a key only your circles phones hold. That key never travels in an invite link: an invite carries a one-time code, and a new member gets the circles keys only after you compare a safety number with them and accept. The relay stores ciphertext it cannot read. Names, avatars, and statuses ride inside that same ciphertext.
Nothing to sign up for
No phone number. No email. No push tokens. Starling runs no analytics, no crash reporting, and makes no third party requests. The only thing it fetches from outside its own server is OpenStreetMap map tiles, and only if you leave the street basemap on. Switch to the Off-grid basemap and the app draws the map locally, with zero network requests.
A zero-knowledge relay
The relay is a small server that moves ciphertext between your circles devices. It sees channel ids, message sizes (padded to a fixed length so they carry no information), timing, and IP addresses, but never a position, a name, or who is in your circle. Every row expires after 24 hours and there are no backups by design. The default relay runs on Cloudflare Workers, so Cloudflare sees the same IP addresses and timing. Tor mode hides your IP from both.
Panic wipe
One action clears the app: local storage, cached data, everything. If you need to disappear from a circle fast, this is the button.
App lock
Optional passcode lock encrypts your circle secret at rest (PBKDF2-SHA-256, 600k iterations). Where the device supports it, your fingerprint or face opens the vault through the Android Keystore, which never leaves the secure hardware on your phone.
Circles, plural
Keep one circle for family and another for the friends you split up from at a fair or a concert. Switch with a tap on the circle name. Every circle has its own key and its own identity, so even the relay cannot tell your groups apart.
SOS and check-ins
Hold to fire an SOS that your circle sees immediately. Check in with a status without leaving your location on all the time.
Live sharing that keeps running
The Android app keeps sharing your location while your screen is off, with a persistent notification the whole time so it is never silent about what it is doing. Swiping the app away ends the share and it picks back up when you reopen Starling, or turn on Keep sharing when the app is closed in Settings and it carries on. Turn it off with one tap; your circle sees stopped instead of a dot that just goes stale.
Self-hostable
Dont want to trust our relay? Run your own. The app has a setting for a custom relay address, and the relay is open source and small enough to read in one sitting. Run it on Cloudflare Workers, or as a plain server on your own VPS or home machine behind Apache or nginx, with no Cloudflare account at all.
Works with Orbot
Per-app VPN mode needs no setup. Turn on Power User Mode in Orbot and Starling proxies directly through its SOCKS port instead.
Honest about its limits
The relay still sees IP addresses and timing, because something has to move your ciphertext around. Keys move forward every ten minutes and the old ones are destroyed, but a phone keeps as much readable history as you let it, up to a day, and that is what a stolen phone can give up. Removing someone re-keys the circle, and nothing re-keys on its own if a phone is compromised without you knowing. All of this is written out, with what is and is not backed by tests, in the projects threat model.
Android 9 and newer
Needs Android System WebView 137 or newer. Android 9 has had no security fixes since January 2022.
Source is on GitHub under GPL-3.0-or-later. Read the code, run the tests, or self-host the relay.
