Privacy Policy
Last updated: 18 October 2026
This policy explains what the Okodus: Sudoku app ("the app") collects, why, and what you can do about it. We try to collect as little as possible.
1. Who we are
The app is provided by Diana Todorova Stancheva, based in the United Kingdom (the "controller" for the purposes of data protection law). Contact: privacy@okodus.com.
2. What we collect and why
| Data | Why | Linked to you? |
|---|---|---|
| A random player ID created on your device the first time you play (your "guest" identity), and a random per-install ID | To run your account and keep your scores and progress in sync | Yes |
| Display name (a name we generate, or one you choose). It is a nickname, not necessarily your real name | To show you on leaderboards | Yes |
| Sign in with Apple identifier (Apple's stable user ID for our app). We do not store your email address | To let you sign in again and restore your progress after a reinstall | Yes |
| Games you finish and their scores, times, mistakes and hints, and the leaderboard totals built from them | To run leaderboards and check scores for fairness. The detailed move list of a game is kept for 90 days for review, then removed | Yes |
| Country of your App Store storefront (a two-letter code). We do not ask for location permission | To support regional leaderboards | Yes |
| Usage analytics: simple events such as app opened, puzzle started, completed or abandoned, hint used, daily puzzle opened, sign-in result, leaderboard viewed, notification permission result, account deleted; each with a few fixed details (for example difficulty and time), plus the app version | To understand how the app is used and improve it | No. Events carry a random per-install analytics ID that is never joined to your player ID. We do not read or store your IP address for analytics |
We do not use third-party analytics SDKs: analytics go to our own server. We do not sell your data.
Like most online services, the hosting providers named in section 5, and Apple and Google, process technical connection data such as IP addresses when your device contacts them, and may keep short-term server logs for security and reliability under their own policies. We do not use IP addresses to identify players or link them to analytics.
3. What stays on your device
Your puzzle progress, saved game, statistics, streaks, settings and a queue of scores waiting to be sent are stored on your device. Deleting your data in the app removes them (see section 7). We do not read your contacts, clipboard, photos or location.
4. Advertising
The free app shows ads from Google AdMob: a banner at the screen edge furthest from the number pad, and an optional rewarded ad that you can choose to watch for an extra hint (at most three per puzzle, no points lost). There are no full-screen ads during play, and ads are muted. No ad is shown before the consent step below, and you can keep playing whatever you choose. The optional one-time ad-free purchase ("Remove ads") removes the ads, and the consent form and tracking prompt will no longer appear for you. After you buy it, the app does not request ads, so no ad data is collected through the app.
- What AdMob may collect. Google and its partners may collect and use device information, such as advertising identifiers, IP address (which can give an approximate location) and ad interaction data, to show, measure and protect ads. See Google's Privacy Policy.
- Consent. Where required (the EEA, the UK and Switzerland, and some US states), the app shows Google's consent message, from Google's messaging tool. It first appears after you finish your first puzzle, back on the home screen, never on first launch and never during a game. Ads are not requested until that step is done.
- Apple's tracking prompt. Right after the consent message, the app asks for permission under Apple's App Tracking Transparency, to show ads that are less irrelevant. If you say no, ads can still appear but are not personalised by tracking across other apps and websites, and the app works the same. You can change this in iOS Settings.
- Change your choices. In the app: Settings, then Privacy choices (shown where consent applies to you).
5. Who we share data with
- Hosting: our server runs on Railway and the database on Supabase. Both are in the EU: the server in Amsterdam (Netherlands) and the database in Frankfurt (Germany).
- Apple: for Sign in with Apple, and the App Store.
- Google AdMob: for ads, as described above.
- Other players: your display name, rank and scores are visible on leaderboards.
Some of these providers may process data outside the UK and the European Economic Area, including in the United States. Where that happens we rely on the safeguards they offer under data protection law, such as adequacy decisions and standard contractual clauses, and on data processing terms with our hosting providers.
6. How long we keep data
- Account, scores and leaderboard data: until you delete your account or data, with the exception described in section 7.
- Detailed game moves: 90 days.
- Analytics events: deleted after 13 months.
- Records that must be kept by law (for example, purchase records once purchases exist) may be kept for the legally required period.
7. Deleting your account or data
In the app, open Settings, then Account, and choose Delete account (if you signed in with Apple) or Delete my data (if you are a guest). You confirm in two steps.
- Guest: your leaderboard entries, submitted games and sessions are removed from our server, and your device data is erased. We keep a minimal record that the ID was deleted, with no name, so the ID cannot be reused.
- Signed in with Apple: your Apple link, sessions and device records are removed, your name is replaced with "Deleted player", and detailed moves are removed. Your scores stay on the leaderboards under "Deleted player" so that other players' rankings stay fair; they can no longer be connected to you by name. We also ask Apple to revoke the Sign in with Apple link. If Apple cannot confirm this, your data is still deleted; you can remove Okodus in your Apple ID settings yourself.
- Analytics: the app forgets its analytics ID. Past analytics events cannot be linked to you and are deleted after 13 months.
If you cannot sign in to delete (for example, you were away more than 90 days), email us and we will help.
8. Children
Okodus is not directed at children, and because the app shows ads and offers an optional online account it is meant for people aged 16 and over. We do not knowingly collect personal data from anyone under 16. If you believe a child has given us data, email privacy@okodus.com and we will delete it.
9. Your rights
Under the GDPR and UK GDPR you can ask for access to your data, correction, deletion, restriction, a portable copy, and you can object to processing. Where we rely on consent (for personalised ads), you can withdraw it at any time through Privacy choices in the app. You can also complain to your data protection authority. To use these rights, email privacy@okodus.com. We may need to verify that you control the account, for example by having you contact us from within the app, and we will reply within one month. Deleting your account or data can be done directly in the app.
Why we may use your data (legal bases). To run your account, scores, leaderboards and sync, and to let you sign in: it is needed to provide the app to you (contract). To check scores for fairness, keep the service secure and understand how the app is used through our own analytics: our legitimate interests in running a fair and safe game, which we balance against your rights, and which do not involve reading your name or contacts. For personalised ads and Apple's tracking prompt: your consent, which you can withdraw. To keep records the law requires, such as purchase records: a legal obligation.
We are based in the United Kingdom and have not appointed a separate representative in the EU. Write to privacy@okodus.com for any request. You may also complain to the UK Information Commissioner's Office (ico.org.uk) or to your local data protection authority.
10. Changes
We may update this policy. The date at the top shows the latest version. We will tell you in the app if a change is important.
11. Contact
privacy@okodus.com. See also the support page and the Terms of Use.