This privacy policy describes how Sudoku Museum ("the app", "we", "our")
handles information when you use it. It applies to the Android app published
under the package name com.grandcurator.
The app is developed and operated by:
Marcel Meijer
Email: info@kynto.eu
You can contact us at the email above for any privacy-related question or request.
When you first open the app we sign you in to Firebase Authentication using anonymous sign-in. This creates a random user ID (UID) on Google's servers. We use that UID to:
We do not ask for your name, email address, phone number, contacts, location, photos, or any other personal information at sign-in.
During onboarding you pick a curator name (3–20 characters, letters / digits / underscore only). This name is stored alongside your UID and shown next to your scores on the global leaderboard. Pick a name that doesn't identify you personally — it's visible to other players.
We store these on Google Cloud Firestore:
When you finish a puzzle, the app sends the puzzle ID, your time, mistake count, and difficulty to a Cloud Function which computes your score and stores the entry under your UID and chosen name. Entries are public (visible on the leaderboard inside the app) but show only your curator name, not your UID.
If you buy something from the in-app shop, Google Play handles your payment. We never see your card details. We do receive a purchase token from Google which we store to prevent the same purchase being claimed twice and to confirm delivery. We do not link your purchase to anything outside this app.
The free version of the app shows ads provided by Google AdMob. AdMob may collect or receive information from your device — including a resettable advertising identifier — to provide and personalise ads. This is governed by Google's Privacy & Terms.
If you purchase the Founder's Pack in-app, all interstitial ads are permanently removed.
We use Firebase App Check to verify that requests come from a genuine, unmodified copy of the app. This involves Google's Play Integrity service. No personal data is collected by App Check — it only confirms the app hasn't been tampered with.
Game data is stored on Google Firebase (Firestore, Authentication, Functions, App Check). We do not sell your information and do not share it with third parties other than:
When you submit a leaderboard score, your curator name and score become publicly visible to anyone using the app's leaderboard screen.
Firebase services may process and store data in data centres operated by Google in the United States and other countries. By using the app you agree to this transfer.
We keep your account data for as long as you keep the app installed and using
it. If you stop using the app for an extended period, or if you ask us to
delete your data, we will remove your users/{uid} document and any
leaderboard entries linked to it.
You can ask us at any time to:
To exercise these rights, email info@kynto.eu from the device where the app is installed (so we can identify your UID via the Settings screen), or include the UID shown in the app's Settings screen. We will respond within 30 days.
You can also stop all data collection by uninstalling the app. Note that uninstalling does not automatically delete your data from our servers — email us if you want it removed.
The app is rated for ages 13 and over. We do not knowingly collect data from children under 13. If you believe a child under 13 has provided us with data, contact us at the email above and we will delete it.
If we update this policy we will change the "Last updated" date at the top. Material changes will be announced inside the app the next time you open it.