Privacy Policy

The short version

We built these apps because we were tired of ads and data harvesting. Our apps show no ads, contain no advertising code, and collect nothing we could sell. We do not know your name, your email address, or who you are, and the system is deliberately built so that we cannot find out.

We do store two things: a scrambled identifier that lets your purchases follow you to a new device, and anonymous measurements of the puzzles you play, which we use to keep the difficulty levels honest. The rest of this page explains exactly what those are and everything else that happens.

What is stored on your device

• Puzzle progress, game state, and statistics
• App settings and theme preferences
• Puzzle packs you have downloaded

This stays on your device and is removed when you uninstall the app.

What is stored on our servers

Your player ID

When you sign in through Google Play Games (or Game Center on Apple devices), the platform gives the app an account identifier. We never store that identifier. Instead we run it through a one-way cryptographic function (HMAC-SHA256) using a secret key held only on our servers, and store the 128-bit result.

Three consequences follow, and they are the whole point of doing it this way:

• The stored value cannot be turned back into your platform account — not by us, not by anyone who obtained our database, and not by anyone who asked us to.
• Each of our games produces a different value from the same account, so nothing in our records connects your use of one game to another.
• Because we never hold the platform's own identifier, we cannot use it to look you up with Google or Apple. We removed the ability rather than promising not to use it.

This identifier is required for the app's backend features to work. It is not something you can turn off while signing in, though the apps are fully playable without signing in at all.

Your purchases

We keep a record of puzzle packs you have bought, stored against the scrambled ID above, so that we can confirm you own something before letting you download it and so your purchases survive reinstalling or changing devices. We never see or store payment details of any kind.

Game progress

Some of our apps can back up your puzzle progress and settings so you can restore them on a new device. At present this applies only to Sudoku by Big T. In our other games, progress lives on your device only — reinstall one of them and your puzzle history starts over.

Puzzle measurements

All of our games send us anonymous measurements about the puzzles you play. They exist for one purpose: checking whether a puzzle we labelled “Hard” is actually hard, so that the difficulty levels mean what they say.

A measurement describes the puzzle, not you. It records which puzzle it was and its difficulty and size, whether you finished or gave up, how long you spent actively playing, how many hints you used, how often you left the board or opened the in-game help, and which comfort settings were switched on at the time — whether the timer was showing, whether errors were highlighted, which input mode and layout you prefer. It is entirely numbers and fixed choices. There is no free-text field anywhere in it, so nothing you type can reach us.

These records are stored against the same scrambled per-game identifier described above. That is what lets us tell one player’s twenty puzzles from twenty players’ one — and because the identifier is different in every one of our games, nothing here connects your play in one game to your play in another.

We also count how often the Share My Stats button opens the share sheet. That is the entire event: which game, and when. We cannot see whether you sent anything, or to whom, or what you wrote.

This is our own server, and it is separate from the Firebase analytics described below. We would rather tell you plainly what we measure than imply that we measure nothing.

Analytics and crash reporting

Our apps use Firebase, a Google service, for crash reporting and basic usage analytics. This tells us that a particular app version crashed on a particular device model, or how many people opened the app this week — the information we need to find bugs and keep the apps working.

Firebase assigns each installation of an app a random ID, which resets if you uninstall and reinstall. That ID is not your player ID, and the two are never connected: we never attach a player identifier to a crash report or an analytics event. We do not collect the Android advertising ID — advertising ID collection is switched off in every one of our apps, and none of them requests permission to read it.

What we never collect

• Names, email addresses, phone numbers, or postal addresses
• Your Google or Apple display name, avatar, or profile
• Location data
• Contacts, photos, files, calendar, messages, or call logs
• Advertising identifiers
• Anything at all for advertising, marketing, or personalisation

When you sign in, the platform offers the app your display name and avatar alongside the account identifier. The app never reads them; they are discarded before anything is sent to us.

Who your data goes to

We do not sell your data, share it for advertising, or hand it to data brokers. Nothing is shared for anyone else's purposes.

We do use service providers who process data on our behalf and under our instructions:

• Microsoft Azure — hosts our backend, database, and the puzzle packs you download.
• RevenueCat — manages purchases and entitlements. RevenueCat receives your scrambled player ID and purchase receipts, never a platform account identifier.
• Google (Firebase) — crash reporting and analytics, as described above.
• Google Play and the Apple App Store — app distribution and payment processing. Their own privacy policies govern what they collect when you buy something.

Server diagnostics

Our backend records ordinary operational diagnostics — which requests were made, whether they succeeded, how long they took. IP addresses are masked before storage and we never keep them. These logs record player IDs only by length, never by value, so a diagnostic record cannot be traced to a player. They are deleted after 90 days.

Retention and deleting your data

Data on your device disappears when you uninstall. Data on our servers is kept for as long as the app is operational, or until you ask us to delete it.

To request deletion, email support@adfreebybigt.com. We will delete your scrambled player ID and everything stored against it. Two things we cannot delete: the record Google Play or Apple keeps of your purchase, which belongs to them and is what lets you restore a purchase later, and server diagnostics, which contain no player identifier and expire on their own within 90 days.

How to request deletion walks through the steps and what we need in order to find your record.

Because the identifier is irreversible by design, deletion is final. We have no way to look up or recover an account afterwards.

Children's privacy

Our apps are not directed to children under 13 and we do not knowingly collect information from them. The apps contain no ads, no chat, no social features, and no user-generated content. If you believe a child under 13 has provided us with information, contact us and we will delete it.

Email list

If you subscribe to our mailing list on this website, we store your email address to send you announcements about our apps. We will not send you promotions for third-party products, and we will not share or sell your address. You can unsubscribe from any email. This is entirely separate from the apps — subscribing is not connected to your player ID, and playing our games does not put you on any list.

Changes to this policy

If we update this policy, we will change the date at the top. We will never change it to start collecting personal data — that would go against everything we stand for.

Contact

Questions or concerns? Reach us at support@adfreebybigt.com.

Big T Technologies LLC