Your privacy is the whole point.
Sudoku Trainer was built to be a quiet, private place to enjoy puzzles. No one is watching. No one is collecting.
- ✓No personal information is collected — not your name, not your email, not anything.
- ✓No tracking, cookies, or analytics. The app does not phone home.
- ✓No accounts, no logins. You just open the app and play.
- ✓No ads, ever.
- ✓Everything stays on your device. Your progress, your stats, your settings — all of it lives on your phone or tablet, and nowhere else.
Get help
Have a question, found a bug, or just want to share an idea? Send a message and a real person will write back.
Or copy this address: sudoku-app@netlinenyc.com
Common questions
Will I see ads?
No. There are no ads in the app, and there never will be.
Does the app work without an internet connection?
Yes. Sudoku Trainer works fully offline. Once installed, it does not need a connection for anything.
Will my progress sync between my phone and my tablet?
Not automatically. Your progress lives on each device individually. If you have iCloud Backup (iPhone, iPad) or Auto Backup (Android) turned on, the operating system can restore your progress when you set up a new device of the same kind from the backup.
I reinstalled the app and my progress is gone — what happened?
App data is included in your device backup only when iCloud Backup (on iPhone or iPad) or Google's backup service (on Android) is enabled in your device settings. If those are off, removing the app removes its local data. We cannot recover it for you because we never had a copy.
How do I reset my statistics?
Open the app, go to Settings, and tap "Reset All Progress" at the bottom.
Can I change the language?
Yes. Open Settings inside the app and switch between English and Russian under "Language".
What information do you have about me?
Nothing. Truly nothing. We do not collect data, and there is no server that knows you exist.
Privacy policy
The short version is in the green box at the top of this page: we don't collect anything, we don't track you, and we don't share your data. The detail below is for anyone who would like a thorough explanation.
1. What we collect
Sudoku Trainer collects no personal information of any kind. The app does not ask for your name, your email, your phone number, your location, your contacts, or any other personal data. There is no sign-up, no log-in, no profile.
2. What we store
The app saves your progress, statistics, and settings on your own device, using the standard storage area provided by your operating system. This is the same place where most apps keep their settings. It is encrypted by your device's operating system at rest.
We do not have a server that holds any of this data. The information never leaves your device through any channel we control.
3. Tracking, analytics, and advertising
Sudoku Trainer does not use cookies, advertising identifiers, analytics tools, crash reporters, or any other third-party tracking technology. There are no advertisements anywhere in the app.
4. Sharing
We do not share, sell, or otherwise transmit any user data, because we do not have any user data to share. There are no partners, advertisers, or third parties involved.
5. Device backups
If you have iCloud Backup turned on (iPhone, iPad) or Auto Backup turned on (Android), your operating system may include the local app data in your encrypted device backup. Those backups are handled entirely by Apple or Google under their own terms and encryption. Sudoku Trainer does not have access to your backups.
6. Children
Sudoku Trainer is appropriate for all ages and is rated 4+. Because the app does not collect any information from anyone, it also does not collect information from children. We comply with the Children's Online Privacy Protection Act (COPPA) and similar regulations.
7. Your rights
Because we hold no information about you, there is nothing to request, correct, or delete on our side. If you want to erase the local data on your device, you can do that at any time from the app's Settings → "Reset All Progress" or by uninstalling the app.
8. Changes to this policy
If this policy ever changes, the updated version will appear on this page with a new "last updated" date below. There is no separate notification because we have no way to contact you.
9. Contact
Questions about this policy? Write to sudoku-app@netlinenyc.com.
Last updated: 26 May 2026.