Onedoku Privacy Policy

Last updated: August 28, 2026

App: Onedoku
Package: com.booom.sudoku2
Applies to version: 1.2.7

1. Overview

Onedoku ("the app") is a Sudoku puzzle game. It is free and supported by ads. Everything works without an account — signing in is optional, and it exists only so your records follow you to a new device or a reinstall.

You can sign in with Google, Apple, or an email address. When you do, we receive your email address. If you don't sign in, the app never asks you for your name, email address, or phone number.

Because the app's target audience includes children, it follows the Google Play Families policy. Every ad request is handled under child-directed rules (non-personalized, content rating limited to G), and the app does not collect or transmit the advertising ID (AAID) — the AD_ID permission itself is removed.

2. Information we collect and process

2.1 Information you provide

None, unless you sign in. The app never asks for your phone number, date of birth, payment details, contacts, photos, or location.

If you sign in, we receive the following. Signing in is optional and every feature works without it.

Method	What we receive	Why
Google	Email address, account display name (if present)	So your records follow you to another device. Your monthly leaderboard entries are tied to that account.
Apple	Email address (if you choose “Hide My Email”, we only receive the relay address Apple creates), name (once, if you provide it)
Email	Email address and password

We do not store your password. Firebase Authentication holds it and the operator cannot read it. Sign-in details are never used for advertising and are never sold to third parties.

2.2 Information generated automatically

Service	Data	Purpose
Firebase Anonymous Auth	Randomly generated user ID (UID) — not linked to a name or email	Issues an anonymous identifier so game records can be stored
Cloud Firestore	Game records tied to the anonymous UID (daily challenge clears, play time, difficulty), and friend invite records (the invite code and who installed with whose code — only a relationship between anonymous UIDs)	Keeps daily challenge history, powers the leaderboard, and grants invite rewards
Firebase Analytics	Usage statistics (screen views, game start/clear events), device and OS information	Improving the service. Ad personalization signals are disabled.
PostHog (product analytics)	The same events sent to Firebase Analytics (screen views, game start/clear, and so on), the anonymous UID, device and OS information, IP address	Understanding usage flow and improving the service. Servers are located in the United States (see "International transfers" below)
Firebase Crashlytics	Crash logs, device model, OS version	Fixing errors
Firebase Remote Config	No collection (receives configuration values only)	Distributing operational settings such as difficulty
Google AdMob (ads)	Device and OS information, IP address, ad impression and click records. No advertising ID is sent.	Serving and measuring ads, and preventing fraud

2.3 Ads — non-personalized, child-directed only

The app sets child-directed treatment (tagForChildDirectedTreatment) on the Google Mobile Ads SDK and limits ad content rating to G (general audiences). Ads personalized to a user's past behavior or interests are not served to any user.

2.3-1 Friend invites

The invite feature stores only a six-character code derived from the anonymous UID and the fact that "this person installed with that person's code". It does not read or store names, contact details, or your address book, and invite links are shared through your device's own share sheet, so the app never learns who you shared with. Rewards (credits) are granted on each device.

2.4 Data stored only on your device

Puzzle progress and clear history, trophies (achievements), daily and weekly mission progress
Credit balance, and settings such as theme, sound, and vibration

This data is stored only in device storage (SQLite and Hive) and is never sent to our servers. Deleting the app deletes it as well.

3. Permissions the app requests

Permission	Why it is needed
`INTERNET`, `ACCESS_NETWORK_STATE`	Loading ads, communicating with Firebase, checking network status
`VIBRATE`	Haptic feedback on input (can be turned off in settings)
`POST_NOTIFICATIONS`	Showing notifications (Android 13 and above)
`RECEIVE_BOOT_COMPLETED`	Restoring scheduled local notifications after a restart

The app does not request advertising ID (AD_ID), location, camera, microphone, contacts, photos, or external storage permissions.

4. Third parties

We do not sell or rent user information. The third-party services included in the app are Google (Firebase, AdMob) and PostHog (a processor acting on our instructions). See Google Privacy Policy, Firebase Privacy, How AdMob uses data, and PostHog Privacy.

5. Children's privacy

The app's target audience includes children. Accordingly the app (1) does not collect the advertising ID, (2) limits every ad to non-personalized, G-rated, child-directed serving, (3) disables ad personalization signals in Analytics, and (4) does not collect contactable personal information such as names or email addresses. If a parent or guardian wants their child's data (game records tied to the anonymous UID) deleted, please write to the contact address below.

6. Your rights and data deletion

Delete on-device data: Android Settings → Apps → Onedoku → Storage → Clear data, or uninstall the app
Delete your account in the app: Settings → Account → Delete account. This removes the account together with what is stored on the server (monthly leaderboard entries, profile, invite records). It appears when you are signed in.
Sign out: Settings → Account → Sign out. This disconnects this device without deleting the account; the progress stored on the device stays.
Request deletion of server data (anonymous UID, game records, invite records): Email the address below and we will delete it without delay. The UID is not shown in the app, so mentioning roughly when you played and which device helps us locate the record.
Turn off notifications: Android Settings → Apps → Onedoku → Notifications

7. Security and retention

All external communication is encrypted with HTTPS (TLS).
Game records stored on the server (Firestore) are kept until you request deletion, and are destroyed without delay once you do.
Crashlytics crash logs follow Google's retention policy (90 days).

8. International transfers

The services below keep their servers outside Korea, so the information in section 2.2 is transferred internationally. The transferred information does not include items that directly identify you, such as your name or contact details.

Recipient	Country	Items transferred	Purpose · retention
Google LLC (Firebase · AdMob)	United States and other countries hosting Google data centers	Anonymous UID, game records, usage statistics, crash logs, ad request data	Providing and improving the service, serving ads / per each service's retention policy
PostHog, Inc.	United States	Anonymous UID, app usage events, device and OS information, IP address	Product analytics / until deletion is requested

If you prefer not to have data transferred, uninstalling the app stops collection, and you may request deletion at the address below.

9. Changes to this policy

When this policy changes we update the "Last updated" date on this page. The Data safety declaration on Google Play is updated at the same time.

10. Contact

App: Onedoku
Package: com.booom.sudoku2
Email: seohcz1@gmail.com

This document is based on the app's source code — the merged permission list in AndroidManifest.xml, the AdMob RequestConfiguration, and the dependencies in pubspec.yaml.