Privacy Policy
The short version. TwentyFour does not collect, send or share any personal data. It has no account system, no advertising and no analytics. Everything you do in the app is stored on your device and stays there.
1. What we collect
Nothing. There is no sign-up, no email address, no name, no device identifier, no advertising identifier and no location access.
The app makes no network requests at all. It declares no network permission on Android, which is enforced by the operating system rather than by a promise in this document.
2. What is stored on your device
To remember your settings and progress, the app writes the following to your device's local preferences storage. It never leaves the device and the app cannot read it from anywhere else:
- your chosen theme, language and difficulty level;
- whether sound and haptic feedback are enabled;
- your last chosen timed-mode duration and sub-mode;
- the puzzles you chose to save to your book;
- statistics you can see in the app, such as puzzles solved, times and hints used, plus your personal bests.
These are your own game records, not personal data about you. They are stored so the app can show them back to you.
3. Third parties, advertising and tracking
There are none. The app ships with no advertising SDK, no analytics SDK, no crash-reporting SDK, no social SDK and no payment SDK, and it contains no tracking code and no cookies. Nothing you do is shared with anyone, because there is no one to share it with.
4. How long we keep it
We keep nothing. Your saved puzzles and statistics exist only on your device and are removed when you:
- uninstall the app or clear its storage;
- use your operating system's "clear app data" function; or
- delete individual saved puzzles from inside the app.
Because we hold no copy, there is nothing for us to delete on request. If you want your records gone, clear the app's storage or remove the app.
5. Children
The app is not directed at children under 13 and does not knowingly collect personal data from anyone, including children. Since it collects no personal data at all, there is nothing to delete and no consent to obtain.
6. Your rights
Because the app collects and stores no personal data, there is no data for you to access, correct, export or erase. Depending on where you live, regulations such as the GDPR and the CCPA give you rights over personal data that an organisation holds about you; this app holds none, so those rights are satisfied vacuously rather than through a request process.
7. Security
All data stays on your device, is not transmitted and is protected by your device's own screen lock, encryption and application sandbox. We cannot be breached through a server because there is no server.
8. Changes to this policy
If a future version of the app changes what it stores or gains any network access, this page will be updated before that version is distributed, and the effective date above will change. Material changes will also be described in the release notes.
9. Contact
Questions about this policy can go to pangkunyi@gmail.com, or by post to Room 8201, Building 9, Nantian No. 2 Garden, Futian District, Shenzhen, Guangdong Province.