This Privacy Policy explains how **LuJan Game Studio** ("we", "us", "our"), based in
Switzerland, handles information in connection with the mobile game **Prime Sudoku**
(the "App"). By using the App you agree to the practices described here.
Prime Sudoku is a single-player puzzle game. You can play completely offline and without
creating an account — puzzles are generated on your device. We do not run our own servers and
we do not sell your personal data. Some optional features rely on Google services (advertising,
leaderboards and in-app purchases), which process certain data as described below.
We do not collect personal data on our own servers. Data is processed only through the Google
services integrated in the App:
- **Advertising (Google AdMob).** In the free version we show interstitial ads. Google's
advertising SDK may collect and process device and usage information — such as a device
advertising identifier, IP address, general (coarse) location derived from the IP address, and
ad interaction data — to serve and measure ads and to limit how often you see them.
- **Leaderboards (Google Play Games Services).** If you choose to sign in with Google Play
Games, your public Play Games profile (player ID and display name) and your puzzle scores are
used to display rankings on per-variant, per-difficulty leaderboards. Signing in is entirely
optional.
- **In-app purchases (Google Play Billing).** If you buy the ad-free upgrade, the purchase is
handled by Google Play. We only receive a signal indicating whether the "Remove ads"
entitlement is active. We never see or store your payment card or billing details.
- **Stored locally on your device.** The App stores your preferences and game data locally — for
example your chosen display name, your purchase (ad-free) status, your local scores, and the
timestamp of the last ad shown. This data stays on your device and is removed when you
uninstall the App (it may be included in an Android device backup if you have that enabled).
- To provide and maintain gameplay and save your progress and settings.
- To display and rank scores on leaderboards (only if you sign in).
- To show and cap advertising in the free version.
- To grant and restore the ad-free upgrade you purchased.
The App uses the following Google services, each governed by Google's own privacy policy:
- Google AdMob — <https://policies.google.com/privacy> and
<https://support.google.com/admob/answer/6128543> (how Google uses data).
- Google Play Games Services — <https://policies.google.com/privacy>.
- Google Play Billing — <https://policies.google.com/privacy>.
- Where required (for example for users in the EU, EEA, UK and Switzerland), the App uses
Google's consent mechanism to ask for your choice regarding personalized advertising before
such ads are shown.
- You can reset or delete your advertising identifier at any time in your device settings under
`Settings → Privacy → Ads`, and you can opt out of ad personalization there.
- You can remove ads entirely by purchasing the ad-free upgrade in the App.
We do not sell your personal data. Information is shared only with the Google services listed
above so they can provide advertising, leaderboards and payment processing on our behalf, and
only as needed for those functions.
Locally stored game data remains until you delete it in the App or uninstall the App. Data
processed by Google (advertising, leaderboards, purchases) is retained according to Google's
policies. Leaderboard scores associated with your Play Games account are managed through Google
Play Games; you can manage or delete Play Games data via your Google account.
We rely on the security measures of the Android platform and of Google's services. No method of
electronic storage or transmission is completely secure, but we take reasonable steps to protect
the limited data the App handles.
Prime Sudoku is not directed to children under the age of 13 (or the equivalent minimum age in
your jurisdiction), and we do not knowingly collect personal data from them. If you believe a
child has provided personal data, please contact us so we can address it.
Depending on where you live (including under the EU/UK GDPR and the Swiss Federal Act on Data
Protection), you may have rights to access, correct, delete or restrict the processing of your
personal data, and to object to certain processing. Because most data is processed by Google or
stored only on your device, you can exercise many of these rights directly through your device
settings, your Google account, or by uninstalling the App. For requests directed to us, use the
contact details below.
Google may process data in countries outside your own, including the United States. Such
transfers are subject to Google's safeguards as described in Google's privacy policy.
We may update this Privacy Policy from time to time. Material changes will be reflected by
updating the "Last updated" date above and, where appropriate, within the App or store listing.
LuJan Game Studio, Switzerland
Support: lujangamestudio@gmail.com