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CalPaper

Privacy Policy

Last updated: May 12, 2026

CalPaper ("the App") is developed and operated by Balazs Huszar ("we", "us", "our"). This Privacy Policy explains how CalPaper processes data when you use the App.

1. Overview

CalPaper is a Windows desktop application that connects to user-selected calendar sources and renders calendar information on your desktop wallpaper.

CalPaper does not operate its own backend for collecting or storing your calendar, weather, or location data. Most processing happens locally on your device. However, when you use connected features, the App communicates directly from your device with third-party services such as calendar providers, weather providers, geolocation providers, ICS hosts, and the Microsoft Store.

2. Data We Process

Depending on which features you use, CalPaper may process the following categories of data:

  • Calendar event titles, start times, end times, and all-day status
  • Calendar names, colors, calendar identifiers, and account identifiers
  • Reminder and alarm metadata associated with events
  • Connection details for imported calendar sources, such as ICS feed URLs
  • Authentication data for connected services, such as OAuth tokens for Google and Microsoft
  • Apple Calendar account email address and app-specific password for CalDAV connections
  • Weather-related location data, including coordinates, region/country hints, timezone hints, and weather results
  • User preferences such as language, theme, layout, visible calendars, wallpaper output settings, and notification settings
  • Diagnostic runtime log entries generated by the desktop app

Supported calendar sources currently include:

  • Google Calendar
  • Microsoft Outlook Calendar
  • Apple Calendar via CalDAV
  • ICS/iCalendar calendar sources

3. How We Use the Data

CalPaper uses processed data only to provide the App's functionality, including:

  • Connecting to calendars selected by you
  • Fetching and caching calendar events for display on your wallpaper
  • Rendering calendar layouts, themes, colors, and per-monitor wallpapers
  • Showing event reminders and notification text when the alarms feature is enabled
  • Fetching and displaying weather information when the weather feature is enabled
  • Saving your settings so the App can remain configured across launches
  • Checking premium subscription state through Microsoft Store APIs
  • Writing limited diagnostic logs needed to troubleshoot desktop runtime issues

We do not use your data for advertising, behavioral profiling, analytics tracking, or selling user data.

4. Calendar and Authentication Services

To connect external calendars, the App communicates directly with the relevant provider from your device:

  • Google OAuth and Google Calendar APIs
  • Microsoft OAuth and Microsoft Graph Calendar APIs
  • Apple iCloud CalDAV endpoints
  • Third-party or self-hosted ICS/iCalendar feed URLs that you add

For Google and Microsoft, authentication uses OAuth flows handled between your device and the provider. For Apple Calendar, the App uses the email address and app-specific password that you provide for CalDAV access. We do not receive your primary Google, Microsoft, or Apple account password through our own servers.

5. Weather and Location Data

If you use the weather feature, CalPaper attempts to determine an approximate location so it can request current weather data.

Location resolution currently uses the following order:

  • Windows system location APIs, if available and permitted
  • IP-based geolocation services
  • System region/timezone hints combined with geocoding

Weather and location-related requests may involve third-party services such as:

  • Open-Meteo weather API
  • Open-Meteo geocoding API
  • ipapi.co
  • ipwho.is

Weather snapshots are cached locally and may include the fetch time, temperature, weather code, approximate coordinates, location source, and location hint text.

6. Local Storage

CalPaper stores data locally on your device for functionality and performance. Local files may include:

  • %AppData%\Calpaper\settings.json for settings, connected sources, OAuth tokens, Apple CalDAV credentials, and related configuration
  • %AppData%\Calpaper\events-cache.json for cached calendar events and alarm metadata
  • %AppData%\Calpaper\weather-cache.json for cached weather and location-related data
  • %AppData%\Calpaper\theme-assets\ for prepared local image assets used during wallpaper rendering
  • %AppData%\Calpaper\app.log for runtime diagnostic logging
  • %AppData%\Calpaper\wallpaper.png and rendered wallpaper outputs used by the App

Some diagnostic logging is reduced in packaged Microsoft Store builds, but local storage still remains part of the App's normal operation.

7. Data Sharing

We do not operate our own server that receives your calendar or weather data.

However, the App does send data directly from your device to third-party services when you use related features, including:

  • Calendar providers you connect
  • Weather and geolocation providers used by the weather feature
  • ICS feed hosts that you configure
  • Microsoft Store services for subscription status and billing

We do not sell your data, rent your data, or run advertising networks inside the App.

8. Third-Party Services

CalPaper may rely on third-party services that have their own privacy terms, including:

  • Google
  • Microsoft
  • Apple
  • Open-Meteo
  • ipapi.co
  • ipwho.is
  • Providers or hosts of ICS/iCalendar feeds that you choose to import

CalPaper does not use third-party analytics SDKs, advertising SDKs, or crash reporting SDKs in the current desktop app build.

9. Security

We take reasonable steps to reduce unnecessary exposure of your data by:

  • Keeping most processing on your local device
  • Connecting directly to providers rather than routing data through our own backend
  • Using provider-supported authentication flows where applicable
  • Limiting normal logging in packaged Store builds

At the same time, you should be aware that some sensitive local data, including OAuth tokens and Apple CalDAV credentials, may be stored in local app files on your device. In the current build, these local credentials are not additionally encrypted by CalPaper. The security of your data therefore also depends on the security of your Windows account, device, backups, and connected provider accounts.

10. Data Retention

Data is retained locally for as long as it remains in CalPaper's local files or is needed for the App to function.

You can reduce or remove locally stored data by:

  • Disconnecting or removing calendar sources in the App
  • Turning off features you do not use, such as weather or alarms
  • Uninstalling the App
  • Deleting the local AppData folder at %AppData%\Calpaper, if you want to remove cached files, settings, and logs manually

The current App does not provide a one-click in-app button that clears every local cache and diagnostic file at once.

11. Legal Basis for Processing (EEA/UK Users)

If you are in the European Economic Area or the United Kingdom, we rely on the following legal bases where applicable:

  • Performance of a contract for processing needed to provide the App's requested functionality
  • Legitimate interests for local caching, rendering, diagnostics, and security-related operation of the App
  • Consent where you choose to enable optional features such as calendar connections or weather/location-based functionality

12. Your Rights

Depending on your jurisdiction, you may have rights relating to access, correction, deletion, restriction, objection, or portability of personal data.

Because CalPaper does not maintain a centralized backend copy of your calendar and weather data, many of these rights are most practically exercised by:

  • Managing or deleting data on your device
  • Disconnecting connected accounts in the App
  • Managing the source data through your calendar provider
  • Contacting the relevant third-party provider whose service you connected

13. Children's Privacy

CalPaper is not specifically directed to children. We do not knowingly operate a service that collects children's personal data through our own backend because the App does not use a CalPaper-operated data collection server. However, use of connected third-party services may still be subject to those providers' own terms and age requirements.

14. Payments and Subscriptions

CalPaper offers optional premium functionality through subscriptions handled by the Microsoft Store.

We do not process or store your payment card information ourselves. Billing, purchase handling, and subscription management are performed by Microsoft. The App may locally store subscription state needed to control premium features and may query Microsoft Store services to refresh that status.

15. Changes to This Privacy Policy

We may update this Privacy Policy from time to time. Updates will be published on this website: https://calpaper.eu/

16. Contact

If you have questions about this Privacy Policy, you can contact:

Balazs Huszar
Email: ahuszarbalazs@gmail.com
Website: https://calpaper.eu/