Privacy policy

The short version

Sudoku: Nine Circles works without an account, and your game (your progress, stars, scores, in-game coins and settings) is stored on your phone.

Some information does leave your phone:

• Ads, served by Google AdMob. Where the law requires it, Google asks for your consent first. On iPhone, Apple also asks whether you allow tracking. Ads may be personalized using your device’s advertising identifier.
• Crash reports, sent to Google’s Firebase Crashlytics whenever the app crashes or hits an error it cannot handle. You cannot switch these off.
• Gameplay statistics, sent to Google Analytics for Firebase only if you allow it. The app asks once, and you can change your answer in Settings at any time.
• Performance measurements and update checks, sent to Expo, the company that delivers the app’s software updates.
• Your cloud progress, if you choose to sign in with Google or Apple. It is stored with Google’s Firebase so you can restore it on another phone. You can delete it at any time, in the app or on our website.
• Purchases, if you buy something in the shop. Google Play or the App Store handle your payment directly; we never receive your card or payment details. If you are signed in to sync your progress, we also receive a record of each hint-pack or coin-bundle purchase (a transaction id, what it credited, and when), so it can follow you to another phone.
• Feedback, if you send it, through a form hosted by Tally.

We do not sell your personal information for money. The rest of this page sets out each of these in full.

Who we are

Sudoku: Nine Circles is published by Boilerplate LLC, 8401 Mayland Dr, Ste A, Richmond, VA 23294, United States. For the purposes of data protection law, Boilerplate LLC is the controller of the personal information described here, except where we say that another company makes its own decisions about it.

For questions about your privacy, or to exercise any right on this page, write to support@boiler-plate.com. For general and business enquiries, use contact@boiler-plate.com. Both reach the same people.

We do not operate servers of our own for this app. Every service the app contacts belongs to another company, and each of them is named below.

Collection of personal information

You can play Sudoku: Nine Circles without telling us who you are. The app has no name or email field, and signing in is optional. This section lists everything the app keeps or sends.

What stays on your phone

Your progress (stars, best times and scores, unlocked entries), your in-game coin history, running totals and your settings are stored in the app’s own storage on your phone. The app does not add encryption of its own to that storage; it is protected by your phone’s security. Uninstalling the app removes it. Your phone’s backup may restore it to a new or reset phone.

Your account and cloud sync

If you sign in from Settings → Account, the app creates an account with Google Firebase Authentication so that your progress can follow you to another phone. You can sign in with:

• Google, on Android and iPhone. Google shares your Google account’s email address, your name and a link to your profile picture with Firebase. The game does not show or use your name or picture.
• Sign in with Apple, on iPhone. The app asks Apple for neither your name nor your email address. Apple gives Firebase a unique identifier for you.

In rare cases where neither option is available, the app can create an account that is not linked to any Google account or Apple ID.

Firebase gives your account an account ID and records when it was created and when you last signed in.

While you are signed in, the app keeps a copy of your game in Google Cloud Firestore, under your account ID. That copy contains:

• your progress on each puzzle (stars, best time and best score);
• your in-game currency history (each earning or spending, and when it happened);
• running totals of what you have done in the game (each entry with the time it happened);
• these settings, so they follow you to another phone: strike mode, auto-removal of pencil marks, skipping story scenes, the timer, board coordinates, the Look and the color-vision setting, large text, reduced motion, how boss ranks are shown, whether the Arcade look has been found, sound effects, music and vibration;
• your login streak (when you last claimed the daily reward, and the streak it made);
• your progress in Learn (the techniques you have mastered, the tiers you have finished, and which tutorials you finished or skipped);
• for any puzzle record changed while developer mode was on, a marker holding the results you earned without it.

Two feedback settings are deliberately not synced: the gesture that opens the feedback form, and whether diagnostics are included. Your analytics choice is not synced either. A choice made on one phone does not become a choice on another.

The app syncs when you sign in, when you open it, when you return to it, and shortly after you finish a puzzle or change a synced setting. It never syncs while you are signed out. Only you, signed in to your own account, can read or change your copy. Our database rules refuse every other request.

If you switch accounts. If you link a Google account or Apple ID that is already linked on another phone, this phone joins that account, and its progress is merged into the account’s copy. The copy saved under the phone’s earlier account stays in Firestore until that earlier account is removed, and we then delete it in our monthly check (see Retention of information). You can also ask us to delete it sooner; see Deleting your account and data. Signing in from signed out to a different account asks first, as described under Retention of information.

Crash reports

When the app crashes, stops responding, or hits an error it cannot handle, it sends a report to Google Firebase Crashlytics. This happens on every installation and cannot be switched off. Crash reports are what let us find and fix problems for every player, not only those who opt in to statistics.

A report contains:

• the technical trace of where the problem happened;
• the app’s version;
• your phone’s model and operating system version;
• whether the app was in the foreground;
• an identifier that Crashlytics creates for this installation of the app.

For errors in the app’s own code, the report also includes the error’s message text, word for word. That text is written by the software, not by you, and it is not designed to contain information about you, but we cannot rule it out. Errors the app records deliberately carry only a short code for where and what went wrong, never message text.

If you have allowed gameplay statistics (below), a crash report may also carry a record of recent statistics events.

We do not attach your account ID, name or email address to crash reports, so we cannot look them up by account.

Performance measurements and software updates, from Expo

The app’s software updates are delivered by Expo (650 Industries, Inc.). Each time the app starts, it checks with Expo for a newer version and downloads it if there is one.

The app also sends Expo measurements of how quickly it starts. Those measurements travel with a description of the app and the device it runs on: the app’s version and update, the operating system and its version, the device model, and the language the device is set to.

The update check and the measurements both carry an installation code, a random identifier that Expo’s software stores on your phone. It is not your name, your account or your advertising identifier. It can survive reinstalling the app if your phone restores it from a backup. None of this can be switched off in the app.

Feedback and messages you send us

You can open our feedback form from the menu, by holding two fingers on the screen, or by shaking the phone. You can turn off the last two in Settings. The form is hosted by Tally (Tally BV, Belgium), which processes what you send on our behalf under a data processing agreement and stores it in the European Union.

Before the form opens, the app shows what it will attach and offers an Include diagnostic information switch, which is on unless you turn it off. When it is on, the app adds these details to the form’s web address:

• which version of the app you are running, including the time this device first ran that version, which changes with every update;
• which kind of device you are on, and what its sound was doing: the music setting, what was playing and how loud, whether a screen reader was on, and the last sound error;
• which screen you were on;
• what was happening in your game: the puzzle, its difficulty, how far in you were, elapsed time, strikes and boss state;
• your difficulty, theme and strike mode settings;
• whether your saved progress is loading correctly.

Because these details travel in the web address, they reach Tally, and the browser your phone opens, as soon as the page loads, before you type anything. With the switch off, none of them are sent. Feedback never includes your name, your email address or your location.

On Tally’s page you can type a description and attach a screenshot. Treat anything you put on that page as reaching Tally and us. A screenshot shows whatever was on your screen. Tally emails us a copy of each submission.

Tally, like any website, receives your device’s IP address when the page loads, whether the switch is on or off.

If you email us, or use our account deletion request form (also hosted by Tally, which asks for the email address you signed in with, how you signed in, and anything that helps us find your account), we receive what you send.

Your IP address

Every service the app contacts sees your device’s IP address: Google (for sign-in, sync, crash reports, statistics and ads), Expo and Tally. An approximate area, usually a town or city, can be worked out from an IP address. We do not receive IP addresses ourselves.

Use and processing of collected information

We use the information above only to:

• run the game, and keep your progress in the cloud and on your other phones when you sign in;
• deliver what you buy in the shop, and keep a record of hint-pack and coin-bundle purchases with your account if you are signed in;
• delete your account when you ask;
• find and fix crashes and errors;
• understand how the game is played, if you allow statistics;
• show ads, which pay for the game, personalized where you and the law allow;
• deliver software updates and measure the app’s speed;
• read and answer your feedback and messages;
• meet legal obligations and protect our rights.

We do not use your information for automated decisions that have legal or similarly significant effects on you.

Legal bases (European Economic Area and United Kingdom).

Purchases

The shop sells two hint packs, a coin bundle, two board themes, removing ads, the Training Pack and the Collector’s Edition. Google Play or the App Store processes your payment entirely; we never receive your card or payment details.

Hint packs and the coin bundle. When a purchase finishes, the app credits the hints or coins to your balance and records the store’s transaction id, what it credited, and when, in your in-game currency history on your phone. While you are signed in with a linked Google or Apple account (see Your account and cloud sync), that history — this purchase record included — syncs to our cloud database so it can follow you to another phone. If you are signed out, it stays on your phone. If you choose to replace this phone’s progress with an account’s copy, the coins and hints on this phone are discarded; Google Play’s and the App Store’s own records of what you bought are unaffected.

Board themes, removing ads, the Training Pack and the Collector’s Edition. Buying one of these unlocks it on your phone only. We do not sync this to our cloud database, whether or not you are signed in. Restore Purchases, in Settings, asks Google Play or the App Store to give the app back what you already own.

We do not sell your purchase history, and we do not use it for advertising. Google Play and the App Store keep their own record of what you bought, under their own policies.

Disclosure of information

We share information only with the companies below, each for the purpose stated, and when the law requires it.

Google’s privacy policy is at https://policies.google.com/privacy. How Google uses information from apps that use its services is described at https://policies.google.com/technologies/partner-sites.

We may also disclose information if required by law, such as to comply with a subpoena, or where we believe in good faith it is necessary to protect our rights, your safety or the safety of others, or to investigate fraud. If Boilerplate LLC is sold or merged, the information we hold may pass to the new owner under this policy.

Retention of information

Information on your phone stays there until you uninstall the app, or until you choose to replace it. If you sign in to an account other than the one this phone last synced with while the phone has progress of its own, the app asks whether to add this phone’s progress to the account or to replace it with the account’s copy; replacing it discards the coins and hints on this phone, bought or earned, and cannot be undone.

Deleting your account and data

In the app: go to Settings → Account → Delete account and data, read what will be deleted, and tap Delete. You may be asked to sign in once more to confirm. If you used Sign in with Apple on an iPhone, you will always be asked, and the app also tells Apple to stop the game’s access. The app deletes your cloud copy first and then your account, and signs you out.

On the web: if you no longer have the app, request deletion at https://boiler-plate.com/nine-circles/delete-account, which links to our request form (https://tally.so/r/68apLJ), or email support@boiler-plate.com with the subject “Delete my Sudoku: Nine Circles account”. We may write back to confirm the request is yours. We will never ask for a password. We will delete your account and its cloud data within 30 days and tell you when it is done.

What deletion does not remove:

• the progress on your phone (uninstall the app to remove it);
• crash reports and statistics, which are not linked to your account (Google deletes them on the schedule above);
• Google’s advertising data (you can reset or delete your advertising identifier in your phone’s settings);
• feedback and emails you sent us (say so in your request and we will delete them too);
• purchase records kept by Google Play or the App Store, under their own policies (we cannot access or delete them for you).

We keep no backups of the cloud copy. For up to one hour after a change, Google’s database keeps the previous version, which it then discards.

Transfer of information

Google, Apple and Expo are based in the United States, and each may process what it receives in the United States and in other countries. Tally, which hosts our feedback and deletion-request forms, is based and hosts its service in the European Union. Your cloud copy is stored in Google Cloud’s nam5 region, a multi-region location in the United States. If you use the app outside the United States, your information is therefore transferred abroad. Where the law requires, these transfers rely on safeguards such as the European Commission’s standard contractual clauses, as each of those companies describes in its own terms and privacy policy. Contact us for more detail.

Region specific notices

European Economic Area, United Kingdom and Switzerland

Subject to the conditions in the law, you have the right to:

• access your personal information;
• correct it;
• erase it;
• restrict or object to its use, including objecting at any time to use based on legitimate interests;
• receive it in a portable format;
• withdraw consent at any time, without affecting what happened before (in the app, turn off Share gameplay statistics, or change your choice in Ad privacy options);
• complain to your data protection authority.

Residents of US states with privacy laws

This part applies to residents of states with comprehensive privacy laws, including California, Colorado, Connecticut, Delaware, Iowa, Maryland, Utah and Virginia, and of any other state whose law gives similar rights.

In the last twelve months, the app has collected these categories of personal information, as those laws define them:

• Identifiers: your account ID and the email address from your Google sign-in (if you sign in), the advertising identifier, the Crashlytics and Firebase installation identifiers, Expo’s installation code and your IP address.
• Internet or other electronic network activity: gameplay statistics (if you allow them), interactions with ads, crash reports and performance measurements.
• Commercial information: a record of a purchase you made in the shop (a transaction id, what it credited, and when), if you are signed in to sync your progress.
• Approximate geolocation: inferred by Google from your IP address. The app never reads your device’s location.
• Audio, electronic or visual information: a screenshot, if you attach one to feedback.

We collected it from you, from your device, and from Google and Apple when you sign in or buy something. We use it for the purposes listed under Use and processing of collected information, and disclose it to the companies listed under Disclosure of information.

We do not collect sensitive personal information as those laws define it. We do not use personal information for profiling that produces legal or similarly significant effects.

Sale and sharing. The app shares the advertising identifier and ad-interaction data with Google for cross-context behavioral advertising (personalized ads). Some state laws call that “sharing” or “targeted advertising”, and some may treat it as a “sale”. We do not sell personal information for money, and we do not knowingly sell or share the personal information of anyone under 16.

Depending on your state, your rights are:

• to know and to access the personal information we hold about you, in a portable form where possible;
• to correct it;
• to delete it;
• to opt out of its sale or sharing, and of targeted advertising (see Do not sell or share my personal information);
• not to be discriminated against for using any of these rights. The app works the same whatever you ask.

The app does not detect opt-out preference signals such as Global Privacy Control, because phone operating systems do not currently send them to apps. Use the controls described below, or email us, and we will act on your request.

California residents may also ask whether we share personal information with third parties for their own direct marketing (“Shine the Light”). We do not.

Other countries

If you live elsewhere, including Australia, Brazil, Canada and New Zealand, you may have similar rights under your local law: to access, correct or delete your information, to withdraw consent, to know which third parties receive it, and to complain to your privacy regulator. We honor these requests wherever we can, whatever the law requires.

How to exercise your rights

Email support@boiler-plate.com. To delete your account, you can also use the app or the deletion page described above.

We will confirm we have received your request within 10 business days, and answer within 45 days. If we need more time, we will tell you within those 45 days, and we may take up to 45 more. Where a shorter period applies to you (for example one month under the GDPR), we will meet it.

We may need to confirm the request is yours. For an account, we do this by matching your request to the Google account or Apple ID it was made with, or by asking you to confirm from the app. For feedback, we match what you tell us about what you sent. We have no identifier for crash reports, statistics or Expo’s records, so we usually cannot find those for you. Google and Expo each accept requests directly.

You may use an authorized agent, and we may ask for proof that they act for you.

Appeals. If we decline your request, you may appeal by replying to our answer with “Appeal” in the subject line. We will respond within 60 days and explain what we did and why. If you are not satisfied, you may contact your state’s attorney general or your data protection authority.

Data analytics

Gameplay statistics are collected with Google Analytics for Firebase, and only if you allow it. After you accept the terms on first launch, the app asks “Share gameplay statistics?”. The answer is off unless you tap Allow. You can change it at any time under Settings → Analytics → Share gameplay statistics. Restoring default settings also turns it off.

When statistics are on, the app sends records of:

• starting, finishing and abandoning a puzzle (its difficulty, how long it took, mistakes, hints and stars);
• using a hint;
• changing a setting.

Google’s software also collects some information automatically once statistics are on, such as when the app is opened, which screens are viewed, app version, device model, operating system, language, approximate location from your IP address, and ad impressions. These records are tied to an identifier that Firebase creates for this installation. The app does not give Google your account ID, name or email with them.

Turning statistics on does not allow Google to use them for advertising. The app refuses Google’s advertising-storage and personalization signals for analytics every time, and does not let analytics collect the advertising identifier (or, on iPhone, the vendor identifier).

Privacy of children

Sudoku: Nine Circles is intended for a general audience aged 13 and over, and is not directed at children under 13. We do not knowingly collect personal information from children under 13. The app has no age check, so the automatic collection described on this page happens on every installation, whoever is using it. Ads are requested as suitable for teens and above.

If you believe a child under 13 has signed in or sent us feedback, contact us and we will delete what we hold.

Do not sell or share my personal information

You can limit how your information is used for advertising:

• Ad privacy options, in the app’s Settings, opens Google’s own privacy form wherever Google offers one for your region. In the EEA and UK it is Google’s consent form, where you can change your answer. In US states with privacy laws, it lets you ask that your data not be sold or shared for targeted advertising, and Google’s software applies that choice.
• Your phone’s settings. On Android you can reset or delete your advertising ID. On iPhone you can turn off Allow Apps to Request to Track, or turn off tracking for this app.
• Email us at support@boiler-plate.com and we will act on your request.

Ads are shown either way; they pay for the game.

Advertisements

Ads are served by Google AdMob, Google’s software running inside the app. The app shows banner ads, full-screen ads between chapters, and rewarded ads you choose to watch for a hint.

When ads start. Google’s ad software does not start until you have accepted the terms and answered the statistics question. Then:

• in the EEA and UK, and wherever else Google requires it, Google’s consent form appears before any ad is requested;
• on iPhone, Google shows a short explanation, and then Apple’s tracking prompt appears, saying “Used to show you ads that are more relevant to you.”

What Google receives. Google’s software collects information on its own account, including your device’s advertising identifier and your interactions with ads, and it can store cookies and similar identifiers on your device. Google’s privacy policy describes it, and it is the description to rely on. We cannot inspect everything Google’s software sends.

• On Android, the app lets Google read the advertising ID. You can reset or delete it in your phone’s settings.
• On iPhone, if you choose Ask App Not to Track in Apple’s prompt, the advertising identifier (IDFA) is not available to Google.

What the app attaches to each ad request: which ad space is being filled, whether the ad may be personalized, and three fixed settings applied on every device: ads must be suitable for teens, the app is not directed at children, and the app is not being used by someone under the age of consent. These are statements about the app, not about you.

When ads are personalized. A personalized ad is one Google chooses using your advertising identifier and your activity in other apps and websites. The app asks for personalized ads only when Google’s consent tool reports that consent was obtained or is not required, and that ads may be requested, and, on iPhone, only if you allowed tracking when Apple asked. Your answers in Google’s form and, on iPhone, Apple’s prompt decide what Google may use. If the consent step fails, the app requests no ads rather than guess.

We never send Google your location, your account ID or your email address. We receive no information about you from Google’s ad software.

Links to other resources

The app links to our website, the feedback and deletion forms, and our legal pages. Opening a link takes you to your browser, and that site receives your request like any other. We are not responsible for the privacy practices of sites we do not own.

Information security

We do not run servers of our own for this app. Your cloud copy is held in Google Cloud Firestore, where our rules let only you, signed in to your own account, read or change it. The app’s own connections to Firebase, Expo and Tally are encrypted. We cannot make the same statement about every connection Google’s advertising software opens. Progress stored on your phone is protected by your phone’s security, not by encryption added by the app. No transmission over the internet can be guaranteed to be secure.

Data breach

If information we control (your account and cloud copy, feedback, or emails to us) is exposed through a security incident, we will investigate and notify the people affected, and the authorities, where the law requires it. We will notify you by email where we have your address, and otherwise by a notice on our website. An incident at Google, Apple, Expo or Tally is theirs to report under their own obligations. We will pass on what we learn where it affects you.

Changes and amendments

October 18, 2026: added the choice the app offers when you sign in over this phone’s own progress, and what replacing that progress discards.

We may change this policy. When we do, we will change the “Last updated” date at the top of this page. If we make a material change, such as collecting a new kind of information or using it in a new way, we will say so on this page. We will not use information we have already collected in a materially different way without your consent where the law requires it.

About this policy

This policy explains how we handle your information. It does not apply to other companies’ practices, which their own policies govern. When you first open the app, we ask you to accept the Terms and this Privacy Policy. Our Disclaimer also applies to the app.

Contacting us

If you believe we have not addressed your concern, you may contact your data protection authority or your state’s attorney general.