Privacy Policy

01 Data controller and scope

This policy covers the Chrona app (package dev.mreysei.chrona) on Android and iOS, developed and maintained independently by mreysei ("the developer", "we"). It does not cover third-party services Chrona may link to (for example, your own Google account), which have their own privacy policies.

Chrona has no backend of its own: it's an app that runs entirely on your device. There is no Chrona database where your data gets stored — this single fact explains most of the answers on this page.

02 Quick summary

For anyone who doesn't want to read the rest:

03 What Chrona doesn't collect

Chrona includes no analytics, attribution or advertising SDK, and never requests any of the following permissions:

• Location (precise or approximate)
• Camera or microphone
• Contacts or call/SMS logs
• Photos, videos or device files
• Advertising identifiers

We don't use any of your data to train third-party models or for personalized advertising, ours or anyone else's.

04 Data that is processed

Google account and Google Calendar (optional)

The "Agenda" face can show your upcoming events. To do that, Settings → Google Calendar lets you sign in with your Google account and grant read-only access to your calendar (scope calendar.readonly). This feature is optional: the app works fully without it.

Sign-in and the calls to the Google Calendar API happen entirely on your device — Chrona asks Google's own servers directly for your upcoming events and shows them on screen; they never pass through a Chrona server, because none exists. We don't copy, log, or analyze the content of your events for any purpose other than displaying them on the Agenda face.

In-app purchases

Chrona offers one-time paid unlocks (faces, themes and the desktop widgets feature) through Google Play Billing (Android) or the App Store (iOS). These platforms process the payment; Chrona never receives or stores card or payment method data. We only receive, from the store itself, the purchased product's identifier and its status (purchased / not purchased), used to unlock that content on your device.

Local preferences and settings

The active theme, the selected face, the language, the brightness and the rest of your preferences are stored only in your device's local storage (shared_preferences). They never leave it.

Desktop widget (optional)

If you buy the Widgets feature, Chrona renders on your own device an image of the chosen face to show it on your home screen. No additional data is generated or transmitted for this.

05 System permissions (Android)

Chrona requests no other permission on Android or iOS.

06 Who it's shared with

Chrona doesn't sell or rent personal data to anyone, under any circumstances. The only third parties involved are:

No other service, advertiser or data broker receives information about you through Chrona.

07 Use of Google APIs

Specifically, regarding the Google Calendar data the Agenda face accesses:

• It's used exclusively to show you your own upcoming events inside the app.
• It's not transferred to third parties, except when required by law.
• It's not used for advertising, ours or anyone else's.
• No human reads it, except with your explicit consent, for security reasons, to comply with the law, or in an aggregated and anonymized form for the internal maintenance of the feature.

08 Retention and deletion of data

• Calendar events: fetched on demand and kept only in memory while the Agenda face is on screen; they're not stored persistently.
• Google session: the access token is kept on the device while you stay signed in. Disconnecting in Settings → Google Calendar removes it immediately.
• Preferences and purchases: stay on the device while the app is installed.
• Uninstalling the app deletes all the local data Chrona was keeping.

You can also revoke Chrona's access to your Google account at any time from your Google account's permissions page, independently of the app. See Manage my data and permissions for the step-by-step.

09 Security

Since there's no backend of Chrona's own, there is no centralized user database that could suffer a breach. Calls to the Google Calendar API and to the app stores always happen over HTTPS. Purchases are verified locally on the device with the public keys issued by each store.

10 Children

Chrona is not directed at children under 13 and does not knowingly collect personal data from children. If you're a parent or guardian and believe a child in your care has provided us with personal data, contact us (see Contact) to have it removed.

11 Your rights

Depending on your country of residence (for example, under the GDPR in the European Union or equivalent laws like the CCPA in California), you may have the right to access, correct, delete or obtain a copy of your data, and to object to or restrict its processing. Since Chrona doesn't keep its own server with your data, exercising these rights is, in practice:

• Access / portability: the calendar events you see are already your own data, managed by your Google account.
• Deletion: disconnect Google Calendar in Settings, revoke access from your Google account, or uninstall the app.
• Questions or further requests: write to us, see Contact.

12 Changes to this policy

If we update this policy in a significant way, we'll change the "last updated" date at the top of this page and, when the change is relevant, mention it in the release notes of the corresponding app version. We recommend checking this page from time to time.

13 Contact

For any question about this policy or about your data, write to contact@mreysei.dev.