Last updated: 28 July 2026
Equation X (“the app”, “we”) is a math and logic challenge app published by KheniTech. This policy explains what personal data we collect, why, and the choices you have. By using the app you agree to this policy.
| Data | Why |
|---|---|
| Email address | To create and secure your account and sign you in (via Firebase Authentication, including Google and Apple sign-in). |
| Display name | Shown on the leaderboard and in duels so other players can recognise you. |
| Account ID | A unique identifier that links your profile, stats and gameplay together. |
| Gameplay data | Your answers, points, level, streak, and duel history — the core of the game. |
| Push notification token | If you enable notifications, a device token so we can alert you about duels. Stored privately; never shown to other users. |
| Device identifier | A device identifier generated by the Meta (Facebook) SDK and sent to Meta with app install and launch events, so we can tell which installs came from our own advertising. This is not the Apple IDFA or the Android Advertising ID. |
| Crash diagnostics | If the app crashes, a crash report — the error and stack trace, the app version, device model and OS version, and a Crashlytics installation identifier — is sent to Firebase Crashlytics so we can find and fix the fault. It does not include your answers or messages. |
| App usage and advertising ID | Google Analytics records app installs, launches, session length and app version, together with an app-instance identifier, your device model, operating system version, language, and an approximate location derived from your IP address (country/region level, not precise), so we can see how many people use the app and whether they come back. It does not record your answers or messages. On Android this is linked to your Android Advertising ID; on iOS no advertising identifier is used. |
We do not collect your precise location, contacts, or photos. The app contains no ads. It includes the Meta (Facebook) SDK, which reports app installations and launches to Meta so that we can measure and improve our own advertising; that is the only thing the SDK is used for. On Android, Google Analytics uses the Android Advertising ID (AAID) to measure app installs and sessions and to build advertising audiences; you can reset it or opt out of personalised advertising in your device settings. On iOS we collect no advertising identifier at all — the app does not include the Apple IDFA and never asks for tracking permission. We do not track you across other apps or websites.
To operate the app: authenticate you, run challenges and 1‑v‑1 duels, maintain leaderboards and stats, and (optionally) send you duel notifications.
We use the Google Analytics data described in section 1 to understand how the app is used — how many people install it, how long sessions last and whether players come back — and, on Android, the Android Advertising ID is also used by Google Analytics to build advertising audiences for our own campaigns. On iOS no advertising identifier is involved.
We also use app install and launch events, reported to Meta as described in section 3, to measure and optimise our own advertising — that is, to see which of our ads led to installs and to make those campaigns work better. We do not sell your data, we do not show ads inside the app, and we do not use your gameplay, email or profile to target advertising to you.
We use Google Firebase (Authentication, Cloud Firestore, Cloud Functions, Cloud Messaging, Crashlytics, Analytics) as our backend infrastructure. Data is processed on Google’s servers under Google’s terms.
We also share data with Meta Platforms (Facebook). The app includes the Meta SDK, which reports app installations and launches — together with the device identifier described in section 1 — to Meta so that we can measure installs generated by our own advertising. Meta processes this data under its own terms. We do not send Meta your email address, display name, answers, points or duel history, Meta does not receive the Apple IDFA or the Android Advertising ID from this app, and we do not track you across other apps or websites.
Apart from Google Firebase and Meta, we do not share your data with any other third parties, and we do not sell your data. We may disclose data where required by law.
Because Google Firebase operates globally, your data may be stored and processed on servers located outside your country of residence, including in the United States. We rely on Google's infrastructure and its contractual and technical safeguards to protect your data wherever it is processed.
Notifications are optional. You can decline them when asked, or turn them off any time in your device settings. Declining does not limit any other feature of the app.
You can permanently delete your account and all associated data at any time, in‑app: Profile → Delete account. This removes your profile, stats, submissions, duel participation and push token, and deletes your authentication record. The action is immediate and cannot be undone. It does not reach app install and launch events already reported to Meta: those are held by Meta under its own terms and we cannot delete them on your behalf — contact Meta to exercise your rights over that data. It also does not reach crash reports already sent to Firebase Crashlytics: those are keyed to a Crashlytics installation identifier rather than to your account, contain diagnostics only (not gameplay content), and age out of Firebase's systems on its standard retention schedule (approximately 90 days). It also does not reach analytics data already collected by Google Analytics: that data is keyed to an app-instance identifier — and, on Android, to your Android Advertising ID — rather than to your account, and it is retained and deleted by Google on its own standard retention schedule. On Android you can reset or opt out of that advertising ID in your device settings.
To request account and data deletion without opening the app, email us at contact@khenitech.com or visit our support page; we will delete your data within 30 days. You may also ask us to access or correct the personal data we hold about you, or withdraw consent for notifications, using the same contact.
We keep your data while your account exists. When you delete your account, your personal data is removed as described above. Anonymous or aggregated records that no longer identify you may be retained.
Data is transmitted over encrypted HTTPS/TLS connections and stored using Google Firebase’s security infrastructure with access controls that prevent other users from reading your email or notification token.
The app is not directed at children under 13 (or the minimum age of digital consent in your country). We do not knowingly collect personal data from children under that age; if we learn that we have, we will delete it promptly. Parents or guardians with concerns can contact us at contact@khenitech.com.
We may update this policy; material changes will be reflected by the “Last updated” date above.
Questions or data requests: contact@khenitech.com.