Summary
Vurro runs on your device. The browser extension stores everything in your browser; the mobile app stores your Substack session and app data on your device. It does not transmit your Substack credentials, account identity, or message content to any Vurro-controlled server.
There is one exception, and it is opt-in: if you turn on notifications in the mobile app, Vurro registers your device's push token with its notification backend so it can send content-free "wake-up" messages. That push token is the only thing Vurro sends off your device. See Notifications for how it works.
Browser Extension
The Vurro browser extension runs entirely on your device. It does not send any data to external servers. All data — including bookmarks, watched users, and settings — is stored locally in your browser using the browser's built-in Storage API.
Vurro requests the following browser permissions:
- storage — to save your bookmarks, watched users, and extension settings locally in your browser.
- Host access to substack.com — to enhance the Substack chat interface with search, filtering, and bookmarking features. Vurro only activates on Substack chat pages.
Mobile App
The Vurro mobile app is a third-party Substack client. Like the browser extension, it runs on your device and talks directly to Substack. The one thing it can send to a Vurro-controlled server is your device's push token, and only if you turn on notifications — see Notifications below.
Signing in
You sign in to Substack inside an in-app web view by entering your credentials directly on substack.com — Vurro never sees your email, password, or 2FA code. After Substack authenticates you, the app captures your Substack session cookie from the web view and stores it on your device in the platform's secure keystore (Android Keystore / iOS Keychain). The web view is then closed.
Subsequent requests to Substack are made directly from your device using that stored cookie. Vurro does not proxy, log, or transmit any of your Substack activity to a third party.
What is stored on your device
- Your Substack session cookie (in the OS secure store)
- Your bookmarks, watched users, in-thread search history, and app settings (in the app's local storage)
- A short-lived cache of recently viewed threads and messages, to make navigation feel instant
All of the above stays on your device. Uninstalling the app removes it.
What is not collected
- No analytics SDKs
- No advertising identifiers
- No crash reporting that includes your data
- No tracking across apps or websites
- No transmission of your Substack credentials, account identity, or message content to Vurro or to any third party other than Substack itself. (If you turn on notifications, the app sends your device's push token to Vurro's notification backend — nothing else. See Notifications.)
Notifications
Notifications are optional. Everything in this section only happens if you turn them on. If you leave them off, nothing described here takes place and nothing leaves your device.
When you enable notifications, the app registers your device's push token with Vurro's notification backend. This is the one thing Vurro now sends off your device to a Vurro-controlled server. The token is sent encrypted over HTTPS.
The backend stores only that push token, along with your platform (iOS or Android) and the build variant. It does not store your Substack credentials, your account identity, or any message content.
On a schedule, the backend sends content-free "wake-up" push messages to your device. There is no message data in them. When your device receives one, Vurro polls substack.com directly using your own on-device session and decides locally whether to show you a notification, based on your filter settings. The message content and the rule evaluation never leave your device.
To stop this, sign out of the app, which unregisters your token from the backend. The backend also automatically prunes tokens that have been inactive for 60 days.
Permissions
The app requests only the permissions needed for its features:
- Internet — to fetch chat content from Substack.
- Camera, photo library, or file access (only if you use the attachment-upload feature) — to select an image or video to send. The selected file is uploaded directly to Substack; Vurro never holds a copy.
- Notifications (if you opt in) — to surface filter-matched messages.
You can revoke any of these in your device's app settings without breaking the app's core functionality.
Deleting your data
Almost all of your Vurro data lives on your own device. The one thing Vurro can hold server-side is your device's push token, and only if you turn on notifications. Everything else stays on your device, with no server-side retention.
You can delete the on-device data at any time by taking one or both of these steps:
- Sign out from within the app. This clears the stored Substack session cookie from your device's secure keystore, and it unregisters your push token from Vurro's notification backend. You'll need to sign back in to Substack to use the app again.
- Uninstall the app. This removes everything Vurro stored on your device — bookmarks, watched users, app settings, and the local message cache — along with the session cookie. After uninstall, nothing about your use of Vurro remains anywhere.
Website
This website (vurro.net) does not use cookies, analytics, tracking pixels, or any third-party services. No data is collected from visitors.
Third Parties
Vurro does not share your data with advertisers, data brokers, or any other third party. The browser extension and mobile app fetch the content you're viewing directly from Substack. The only exception is the opt-in notification backend described above, which Vurro operates itself and which receives only your device's push token. No analytics, no advertising networks, no crash reporters that include your data.
Changes
If this policy changes, the updated version will be posted here with a new "last updated" date.
Contact
Questions or concerns? Open an issue at github.com/longcut/vurro-issues.