Privacy Policy — Inkletter.app

Last updated: June 2026

Who we are

Inkletter.app is an Android newsletter reader designed for E-Ink e-readers. Contact: admin@inkletter.app.

Gmail data

Email address of your Google account (identification of the connected account).
Metadata and content of emails identified as newsletters (presence of the List-Unsubscribe header), via the Gmail API in read-only mode (scope gmail.readonly).

Analytics and usage measurement

Inkletter uses Firebase Analytics and Google Analytics 4, configured via Google Tag Manager, to measure app usage (e.g. launches, screens viewed, interaction events). This data is collected and processed by Google. It does not include the content of your Gmail messages.

Purpose: aggregated usage statistics and product improvement.
No targeted advertising based on your newsletter content.
Learn more: Google Privacy Policy.

Use of Google data (Limited Use)

Inkletter.app's use of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements. Specifically:

Gmail data is used solely to display your newsletters in the app and is processed locally on your device (cache).
App usage data (analytics) is transmitted to Google (Firebase Analytics / GA4) as described above.
No Gmail data is sold or used for targeted advertising.
No human reads your data.

Storage

OAuth tokens: encrypted on the device (Android Keystore via Expo SecureStore).
Reading cache and preferences: local device storage only.
No remote database for your newsletter content.
Analytics usage data: sent to Google (Firebase Analytics / GA4 via Google Tag Manager).

Sharing

Your newsletter content is not shared with third parties. Network communications include Google's official APIs (Gmail, OAuth) and Google Analytics / Firebase services for app usage measurement (HTTPS only).

Retention and deletion

Data remains on your device. Signing out (Settings → Sign out) or uninstalling the app removes tokens and local cache. You can also revoke app access from your Google account: myaccount.google.com/permissions.

Changes

Any changes to this policy will be published on this page with a new update date.