NineFold — Privacy Policy

Last updated: 11 September 2026

NineFold is a Sudoku game for iPhone and Android, published by the developer of ninefoldhq.com. This policy explains what the app does and does not do with information about you. It is written to be read, not to be survived.

The short version

NineFold has no account, no login, no server and no cloud sync. Your puzzles, your progress, your times, your streaks and your settings are stored on your device only, and nobody — including us — can read them. We have no analytics and no crash reporting.

The app does contain two third-party services, and they are the only parts of it that involve anyone else: Google AdMob, which shows ads in the free version, and Apple’s App Store / Google Play, which handle the optional NineFold Pro purchase.

What stays on your device

All of it:

• the puzzles you play, your progress in them, and your undo history;
• completion times, best times, streaks, hints used and mistakes;
• your theme choice and other settings;
• the record that you bought NineFold Pro, so it keeps working offline.

None of this is transmitted anywhere. It is removed when you delete the app.

Advertising (free version only)

The free version shows ads supplied by Google AdMob: full-screen ads between puzzles, and optional short videos you can choose to watch in exchange for an extra hint. To show them, the AdMob SDK may collect and process information including your advertising identifier, IP address, device and operating-system details, and coarse location derived from your IP address. Google uses this to select and measure ads. We never receive it.

• Where Google’s consent framework requires one — the EEA, the UK and Switzerland among them — a Google-provided consent form appears before any ad is requested, and your answer decides whether the app asks for personalised or non-personalised ads.
• On iOS, the App Tracking Transparency prompt appears before the advertising identifier is used. If you decline, the app still works exactly the same and you still see ads — just less relevant ones.
• Google’s own handling of this data is governed by its policies: How Google uses information from sites or apps that use our services.

NineFold Pro removes all advertising, and with it everything in this section.

Purchases

NineFold Pro is a one-time purchase handled entirely by Apple or Google. We never see your payment details. The app asks the store whether this account owns the product and records the answer locally so that Pro keeps working when you are offline.

Children

NineFold is a general-audience app. It is not directed at children, and we do not knowingly collect information from children.

What we do not do

• We do not sell or share your information, because we do not have any.
• We do not track you across other apps or websites.
• We have no analytics, no telemetry and no crash reporting.
• We do not use your data to train anything.

Your choices

• Ads: buy NineFold Pro to remove advertising entirely, or change your consent choice at any time from Settings → Privacy → Privacy choices, which reopens Google’s form. That row is present whenever there is a form behind it to reopen.
• Tracking (iOS): change it under Settings → Privacy & Security → Tracking.
• Advertising identifier: reset or limit it in your device settings.
• Everything else: deleting the app deletes all of it. There is nothing held elsewhere to request or erase.

Changes

If this policy changes, the date at the top changes with it, and the current version is always at this address.

Contact

Questions about this policy: privacy@ninefoldhq.com