Privacy Policy

This policy covers the website buzzer-knockout.app (formerly buzzer.staris.services) and the iOS app Buzzer Knockout.

This is a courtesy translation; the German version is legally authoritative.

1. Controller

Stavros Petropoulos
Wehrstraße 2
73035 Göppingen
Germany
Email: sp@staris.services

2. This website

The website is a purely static information page. It sets no cookies, embeds no external fonts or trackers, and performs no analytics. When you visit, our server (located in Germany) processes technically necessary access data in server log files (IP address, date/time, requested address, browser type) to deliver the page and ensure security. Legal basis: Art. 6(1)(f) GDPR (legitimate interest in secure operation). Log files are retained briefly and deleted automatically.

When you open an invite link (/join/?c=…), the room code it contains is read and displayed only in your browser. As part of the requested address, it may appear in the server log file. Links to the App Store lead to Apple; the app banner (“Smart App Banner”) is shown by Safari itself without sending any data to us.

3. No account; storage on your device and in iCloud

The app requires no user account and no registration. Game progress, statistics, the in-game currency (“Sparks”), purchases and settings are stored on your device.

If you are signed in to iCloud on the device, the app additionally backs up your Sparks, the status of your purchases and your progress in Apple’s iCloud key-value storage, so they survive a reinstall or a device change. This data lives in your personal iCloud account; we have no access to it, and it is not sent to our server. The provider is Apple (Apple Distribution International Ltd., Hollyhill Industrial Estate, Hollyhill, Cork, Ireland); Apple’s Privacy Policy applies. Legal basis: Art. 6(1)(b) GDPR (providing your purchases and game progress). The data remains in your iCloud account until the app overwrites it; you manage iCloud in iOS Settings under “[Your Name] → iCloud”.

4. Online multiplayer (our own game server)

For online matches (Quick Match, private rooms, rematch) the app connects to our game server buzzer.staris.services (hosted in Germany). Game Center is not required; you can also play with a nickname of your choice. During an active match it transmits: your displayed player name (nickname or Game Center alias), your chosen color, your cosmetic selections, and your stopped times or estimates for the round. This data is processed only transiently in memory for the duration of the match, serves to run the game, and is not stored persistently and not kept in any database. Your IP address is processed temporarily to maintain the connection.

If nobody is in the Quick Match queue, you play against clearly labeled practice opponents simulated by the server. An invite link contains only the 6-digit room code; you decide whom you send it to.

Legal basis: Art. 6(1)(b) GDPR (running the online game at your request); for the technical connection and abuse prevention, Art. 6(1)(f) GDPR (legitimate interest in stable game operation).

5. Daily Challenge

In the Daily Challenge, everyone worldwide plays the same target time with three attempts per day. For the global leaderboard, our server in Germany stores: your nickname, a randomly generated installation ID (not a device, advertising or Apple identifier) and your results (deviations, number of attempts, date). The installation ID is used to attribute your attempts and enforce the three-attempt limit. Your nickname and results are visible to other players on the leaderboard. Your IP address is processed technically for the transmission.

Retention: entries are deleted automatically after 30 days. If you would like them removed sooner, contact us. Legal basis: Art. 6(1)(b) GDPR (taking part in the Daily Challenge at your request); for the attempt limit and protection against manipulation, Art. 6(1)(f) GDPR (legitimate interest in a fair leaderboard).

6. Game Center (Apple)

The app can use Apple Game Center, e.g. for leaderboards and achievements. If you sign in to Game Center, Apple processes the associated data (e.g. player alias and identifier) as an independent controller. Apple’s Privacy Policy applies. Game Center is optional; online play and the Daily Challenge work without it.

7. Advertising (Google AdMob), consent dialog & App Tracking Transparency

The app is funded by Google AdMob advertising. The provider is Google Ireland Limited, Gordon House, Barrow Street, Dublin 4, Ireland. Google’s Privacy Policy applies.

• Consent dialog (EU, EEA, United Kingdom): On first launch, the app shows a consent dialog from the Google User Messaging Platform, which follows IAB Europe’s Transparency & Consent Framework (TCF). There you decide whether Google and the advertising partners listed in the dialog may store and access information on your device and process data (e.g. device identifiers, approximate location derived from the IP address, interactions with ads) for personalized advertising and ad measurement. This consent determines whether you receive personalized ads. Your choice is stored on the device and passed to Google.
• App Tracking Transparency (ATT): In addition, iOS asks whether the app may track you across apps. Only if you also agree here may your device’s advertising identifier (IDFA) be used. ATT does not replace the consent dialog; it is an additional requirement. Outside the EU, EEA and United Kingdom, ATT alone determines whether the IDFA is used.
• Without consent, only non-personalized or limited ads are shown. Even then, Google processes technically necessary data (e.g. IP address, device type, operating system) to deliver ads, cap their frequency and prevent fraud.
• After purchasing “Remove Ads” or “Buzzer Knockout Plus”, no more ads are shown.

Legal basis for personalized advertising, ad measurement and access to your device: your consent under Art. 6(1)(a) GDPR in conjunction with Section 25(1) of the German TDDDG. Legal basis for non-personalized ads: Art. 6(1)(f) GDPR (legitimate interest in funding the app through advertising). Your consent choice stays stored on the device until you change it or delete the app; how long Google and its advertising partners keep data is governed by their privacy notices.

Withdrawal: You can change or withdraw your choice at any time with effect for the future – in the app under Settings → “Privacy Settings”. You change the ATT permission in iOS Settings under “Privacy & Security → Tracking”.

8. Anonymous usage statistics (TelemetryDeck)

To understand which features are used and to improve the app, it sends anonymous usage signals (e.g. “game started”, selected mode, app and iOS version, device type, language) to TelemetryDeck (TelemetryDeck GmbH, Germany). No personal data such as name, nickname, email address or location is transmitted. Instead of a device or advertising identifier, a randomly generated installation ID is used, which is only transmitted in hashed form. TelemetryDeck does not store IP addresses. TelemetryDeck processes the data on our behalf (Art. 28 GDPR); TelemetryDeck’s Privacy Policy applies in addition.

Legal basis: Art. 6(1)(f) GDPR (legitimate interest in improving the app and fixing errors). Signals are stored only as long as necessary for this analysis. You can turn the statistics off at any time in the app under Settings → “Privacy Settings”.

9. Crash reports (Apple MetricKit)

If the app crashes or stops responding, iOS provides technical diagnostic data via Apple’s MetricKit interface (e.g. type of error, code location, app and iOS version, device type). The app forwards these reports anonymously to TelemetryDeck (see section 8); they contain no personal data. Legal basis: Art. 6(1)(f) GDPR (legitimate interest in a stable, error-free app).

10. In-app purchases

Purchases (e.g. “Remove Ads”, “Buzzer Knockout Plus”, Spark packs, task card packs, Premium Pass) are handled entirely by Apple (StoreKit). We receive no payment data; the app is only informed of the entitlement status to unlock content. This status is stored on the device and in your iCloud account (see section 3). Legal basis: Art. 6(1)(b) GDPR (performance of the purchase contract).

11. Notifications

With your permission, the app may send you notifications (e.g. a reminder that the Buzzer Pass season is ending). These are scheduled as local notifications on the device; no data is sent to a push server for them.

12. Recipients & international transfers

Data is transferred only as described above:

• Apple (App Store and in-app purchases, iCloud, Game Center, MetricKit) as an independent controller,
• Google and – only with your consent – the advertising partners listed in the consent dialog (advertising),
• TelemetryDeck GmbH, Germany, as a processor (anonymous statistics, crash reports),
• our own game server in Germany (online play, Daily Challenge).

Using Apple’s and Google’s services may involve processing in third countries (e.g. the USA); the providers rely on appropriate safeguards (including EU Standard Contractual Clauses / the EU-US Data Privacy Framework).

13. Your rights

Under the GDPR you have the rights of access (Art. 15), rectification (Art. 16), erasure (Art. 17), restriction (Art. 18) and data portability (Art. 20). You can withdraw any consent you have given at any time with effect for the future (Art. 7(3)), in the app under Settings → “Privacy Settings”. You also have the right to lodge a complaint with a data protection supervisory authority, e.g. the State Commissioner for Data Protection and Freedom of Information of Baden-Württemberg. To exercise your rights, contact sp@staris.services.

Right to object (Art. 21 GDPR): Where we process data on the basis of Art. 6(1)(f) GDPR (e.g. anonymous statistics, crash reports, game operation), you may object at any time on grounds relating to your particular situation. You can also turn off the anonymous statistics directly in the app’s privacy settings.

14. Changes

We update this policy when features or the legal situation change. The version published here applies.

Last updated: September 27, 2026.