Effective date: 11 October 2026 · Last updated: 11 October 2026
This Privacy Policy explains how Marble Trails (“the app”, “we”, “our”) collects, uses and protects your information when you play. By installing or using the app, you agree to the practices described below.
Questions about this policy: nguyenduyanhuit1989@gmail.com.
The short version. There is no sign-up and no account. We never ask for your real name, email, phone number, photos, contacts or precise location. The game itself runs on your device. What leaves it: your chosen nickname, country flag and scores for the two leaderboards; anonymous crash reports and gameplay/purchase events (Firebase); and, for ads, the advertising identifier and IP address used by Google AdMob. Store purchases are paid through Apple or Google — we never see payment details. Erase your leaderboard rows and local data from Settings → Delete my data, inside the app.
1. Information we collect
1.1 Stays on your device
Stored locally and never uploaded:
- Your settings — sound effects, music, vibration, language and reminders.
- Your coin balance, owned tools and looks, reward claims (level stars, the daily gift) and the identifiers of coin-pack purchases already credited (so a purchase the store reports twice is never credited twice).
- Your progress — which levels you have cleared, the stars and best score on each, and your best Endless run.
- Lifetime statistics such as games played, shots fired and your longest chain.
1.2 Published to the leaderboards
The app has two leaderboards: Levels (the sum of your best score on every level, with your stars and levels cleared) and Endless (your best Endless score and the wave you reached). A row needs a label, so before your first game the app asks for a display name and a country — it suggests a name and pre-selects the country your device reports, and you may change either. When you finish a level or an Endless run, or open the leaderboard, and you have a score above zero, we store:
- the nickname you chose or accepted (2–20 characters, screened for offensive words);
- the country you picked, shown as a flag;
- your Levels total, stars and number of levels cleared, and your best Endless score and wave;
- an anonymous identifier generated by Firebase Authentication, which is not linked to any account, email or device identifier and exists only so your own rows can be updated and deleted.
Nothing else is published. We do not upload your shots, your settings or your statistics.
1.3 Collected automatically
| Data | Why |
|---|---|
| Crash reports and error logs (device model, OS version, stack trace) | To find and fix crashes. Firebase Crashlytics. |
| Anonymous usage events — which level or mode was started, whether it was won or lost, screen views | To understand which parts of the game are played and which levels are too hard. Firebase Analytics. These events never contain your nickname, country or any free text. They also record a store purchase (the product only, never the price, account or payment details) and what coins were spent on. |
| Advertising identifier (IDFA on iOS, Advertising ID on Android) and IP address | Used by Google AdMob to serve and measure ads, and to estimate an approximate region. See section 2. |
2. Advertising
The app shows ads supplied by Google AdMob: a banner at the bottom of the menus, and an occasional full-screen ad after every few finished levels or runs, shown only after the result. No ad is shown over the board while you are playing, and nothing in the game is locked behind an ad. Buying Remove Ads turns the banner and the full-screen ads off for good on that store account.
AdMob may use your device’s advertising identifier to select ads and measure them, which constitutes tracking under Apple’s definition. Your choices:
- iOS: the app asks for permission through Apple’s App Tracking Transparency prompt. If you decline, you still get ads, but non-personalised ones. You can change your mind at any time in Settings → Privacy & Security → Tracking.
- Android: you can reset or delete your Advertising ID in Settings → Google → Ads.
- European Economic Area, UK and Switzerland: the app shows Google’s consent form on first launch and honours your choice. You can reopen it from the app, in Settings → Ad privacy choices.
Ad content is capped at the “G — General audiences” rating, and sensitive categories (gambling, alcohol, dating, politics, references to sex) are blocked at the account level.
3. Third-party services
| Service | What it receives | Policy |
|---|---|---|
| Google AdMob | Advertising identifier, IP address, coarse ad-interaction data | policies.google.com/privacy |
| Firebase Crashlytics | Crash traces, device model, OS version | firebase.google.com/support/privacy |
| Firebase Analytics | Anonymous gameplay events, anonymous identifier | firebase.google.com/support/privacy |
| Firebase Authentication (anonymous) | Nothing you provide — it mints an anonymous id | firebase.google.com/support/privacy |
| Apple App Store / Google Play | Processes in-app purchases (we receive only a transaction identifier) | apple.com/legal/privacy · policies.google.com/privacy |
| Cloud Firestore | Your two leaderboard rows only: nickname, country and scores | firebase.google.com/support/privacy |
We do not sell your data, and we do not share it with anyone beyond the services above.
4. Purchases
The app offers optional in-app purchases: coin packs (consumable) and Remove Ads (a one-time purchase). Payments are processed entirely by the Apple App Store or Google Play under their own terms; we never receive or store payment information such as card numbers or billing addresses. The store tells the app only that a purchase succeeded, with a transaction identifier, which the app keeps on the device to credit each purchase once. Coins (earned or bought) live only on this device and have no cash value. Remove Ads can be restored on a new device with Restore purchases (in the Armory and in Settings).
5. Your rights and choices
5.1 Deleting your data — in the app
Open Settings → Delete my data and confirm. This removes, in one action:
- your rows on both leaderboards on our servers, including your nickname and country;
- every local setting, level record, score and statistic on the device, your display name, and your coin balance (including coins bought in packs), tools, looks and reward claims. Remove Ads, if you bought it, is kept: deleting your data is a privacy control, not a refund.
The action is irreversible and requires no email to us. If the device is offline, the app deletes the local data and tells you that the leaderboard rows could not be confirmed — run it again once connected. Settings → Reset progress only clears your progress on the device; it does not remove your leaderboard rows. Uninstalling the app removes local data but not a leaderboard row — so use Delete my data first.
5.2 Other choices
- Change your nickname or country at any time in Settings → Display name.
- Turn reminders off in Settings → Reminders or in your device settings.
- Opt out of personalised ads as described in section 2.
- Write to nguyenduyanhuit1989@gmail.com to ask what we hold about you. Because there is no account, please include the nickname you used so we can find the row.
6. Notifications
The app can send local reminders — an evening nudge to play, and a note if you have not played for a day, three days or a week. They are scheduled on your device by your device; no notification is pushed from a server, and no notification contains personal information. Permission is asked for once and can be revoked at any time.
7. Children’s privacy
The app is intended for ages 13 and over and is not directed at children under 13. We do not knowingly collect information from children under 13. If you believe a child has provided information, contact us and we will remove it.
8. Security
Data in transit uses HTTPS. Leaderboard rows are protected by server-side rules that let signed-in players read the public boards but write and delete only their own rows. Because we collect no passwords, email addresses or payment details, there is no credential of yours for us to lose.
9. Data retention
Local data stays until you delete it or uninstall. A leaderboard row stays until you delete it. Crash and analytics data is retained according to Google’s Firebase retention settings.
10. Changes to this policy
If this policy changes we will update the “Last updated” date above, and material changes will be noted in the app’s release notes.
11. Contact
Dragonball Studio — nguyenduyanhuit1989@gmail.com