Muninn

Privacy Policy

Last updated: October 25, 2026

Muninn is an offline journaling app. This policy explains, plainly, what happens to your data — the short version is: it stays on your phone.

The short version

Everything you write stays on your device, encrypted, and is never uploaded anywhere.
Muninn has no account system, no server, and no backend of any kind for your journal content to be sent to — even if we wanted to collect it, there's nowhere for it to go.
The AI writing-prompt feature runs entirely on your device. Nothing you write is sent to us, to Google, or to anyone else for that feature to work.
We collect no analytics, no advertising data, and no crash reports.
We don't sell or share your data, because we don't have your data.

What's stored, and where

Data	Where it lives	Ever leaves your device?
Journal entries you write	Encrypted local database on your device	No
Mood tags you select	Encrypted local database on your device	No
AI prompt history (which question led to which sentence)	Encrypted local database on your device	No
App Lock on/off and timeout setting	Encrypted local storage on your device	No
Local usage counts (e.g. how many times you've used the AI-expand feature)	Plain local storage on your device	No

Your journal database is encrypted at rest using SQLCipher with a randomly generated key that itself is stored in your device's secure hardware-backed keystore. Muninn also opts out of Android's automatic cloud backup for app data, so your journal isn't even incidentally copied off your device that way.

The on-device AI feature

When you tap “Help me expand this,” Muninn runs a small language model (Gemma 3, via Google's LiteRT-LM runtime) directly on your phone's hardware. Your journal text is read by that on-device model to suggest a question — it is never transmitted over the network, to us, to Google, or to anyone else, at any point in that process.

The model itself is a large file (~584MB) that your device downloads once, on request, through Google Play's Asset Delivery service — the same system Android uses to deliver app updates. That download transfers only the model file; it does not include anything you've written. Google's own Play Store services necessarily see standard delivery information (like any app install or update) as part of operating that download — that's Google acting as the platform, governed by Google's own privacy policy, not something Muninn adds or has access to.

App Lock (optional)

If you turn on App Lock, Muninn asks Android's own biometric system to confirm it's you — using your fingerprint, face, or device PIN. Muninn never receives, sees, or stores your actual fingerprint, face data, or PIN; the operating system handles that entirely on its own secure hardware and only tells Muninn “yes” or “no.”

Permissions Muninn uses

Internet — used only for the one-time, user-initiated download of the on-device AI model described above. Never used automatically, never used to transmit your journal content.
Biometric permissions — used only for the optional App Lock feature described above, and only when you turn it on.

Muninn's AI-download component also carries a small number of permissions (background-service, network-state, and boot-related permissions) that come from Google's Play Asset Delivery library itself, so a model download can resume reliably after you close the app or restart your phone. These exist to manage that one-time file download; they are not used to collect or transmit any personal or journal data.

Children's privacy

Muninn is not directed at children and does not knowingly collect any information from anyone, regardless of age — because Muninn does not collect information from anyone, full stop.

Changes to this policy

If this policy ever changes, the update will be posted here with a new “Last updated” date.