Privacy Policy

Who is responsible

Lumistack is published by Çetin Arda Gücer.

Privacy questions: lumistacksupport@gmail.com.

Data stored on your device

Your progress, stars, coins, boosters, settings, reminder choice and analytics choice are stored on your device. This data stays on the device until you reset progress or delete the app.

The optional daily reward reminder is a local notification scheduled on your device. The app has no push notification server and does not send a notification token anywhere.

Cloud backup and anonymous sign-in

The app signs you in anonymously with Firebase Authentication. You are not asked for a name, email address or password, and the app does not link this anonymous ID to your identity.

The app backs up your game progress to Cloud Firestore under that anonymous ID. Cloud backup is on by default. To delete your cloud copy, open Settings, go to Data and choose Delete my cloud data. This deletes your cloud save and your anonymous Firebase account. Until you turn cloud backup on again, the app does not sync.

Duels

When you create a duel or join one, the app stores the duel board, your result (whether you won, number of moves and time taken) and your anonymous ID in Cloud Firestore.

Any signed-in player with the duel code can see the board and the results recorded for it, including the anonymous IDs. Each duel is deleted automatically 30 days after it is created. Deleting your cloud data also removes the duels you created and your own results. Results that friends recorded on a duel you created stay until the duel expires, 30 days after it was created.

Analytics and error reports (PostHog)

The app sends product analytics to PostHog, a product analytics service. Analytics events describe gameplay, for example that a level was started or completed, or that a screen was opened. PostHog assigns the app an anonymous identifier. We use these events to balance levels and fix problems.

When you report a level, the app sends the level, the reason you picked and the app language. Reports do not include free text.

The app also sends error reports to PostHog. They contain the error message, the app version, the language setting and where in the app the error happened, such as a screen name. File paths and long strings that look like tokens are removed before sending. Error reports do not include your coin balance, purchase details or anything you typed.

Settings has a switch called Share anonymous usage data. It is on by default. When you turn it off, the app stops sending analytics events and error reports at once, and the choice stays in place after you restart the app. Turning it off does not delete data that was already sent. To ask us to delete that data, use the contact address below.

Like any internet request, these events reach PostHog with your device's IP address. PostHog discards the IP address of each event (IP anonymization is on for the project).

Purchases

Coin packs are sold through the Apple App Store or Google Play. The store processes the payment. We do not receive or store your card or payment details.

Lumistack uses RevenueCat to check purchases and to restore them. RevenueCat receives an anonymous app user ID and your purchase history for the app. You can restore earlier purchases from Settings.

Advertising and tracking

Lumistack includes no advertising SDK. The app does not use the advertising identifier, does not ask for App Tracking Transparency permission, and does not share data with advertisers or data brokers.

Children

Lumistack is for a general audience. It is not directed at children, and we do not knowingly collect personal data from children under 13. If you think a child has sent us data, contact us and we will delete it.

How long data is kept, and how to delete it

• On your device: until you choose Settings, Reset progress, or delete the app.
• Cloud backup: until you choose Settings, Data, Delete my cloud data.
• Duels: deleted automatically 30 days after they are created, or earlier when you delete your cloud data.
• Analytics: you can stop sending it with the Share anonymous usage data switch in Settings. Analytics and error reports already sent are kept in PostHog until they are deleted by us or at your request. Ask us to delete them using the contact address above.
• Purchase records: kept for as long as needed to verify and restore your purchases and to meet tax and accounting rules. Ask us to delete them using the contact address above.

Your rights

Depending on where you live, you may have the right to ask what personal data we hold about you, to correct it, to have it deleted, or to object to its use. Contact us at the address above and we will answer.

Changes to this policy

When this policy changes, we update the date at the top of this page. If a change affects how we use data already collected, we will say so on this page before it applies.