1. Who we are

Plus & Minus (덧셈 뺄셈, “the app”) is developed and published by Innomote LLC (“we”, “us”). This policy covers the app on iPhone, iPad, and Android. Contact: support@innomote.com

2. Information we collect

None. The app does not ask for or collect names, email addresses, phone numbers, photos, voice recordings, contacts, location, advertising identifiers, or any other identifier, and it sends nothing to us. It contains no advertising, analytics, crash-reporting, or social-media tools. The only network traffic comes from the App Store or Google Play when they handle the purchase (section 6), and from your web browser if a grown-up opens this policy from the app’s Settings.

If you allow sharing with app developers in your device settings, Apple or Google may give us crash reports and statistics that they collect under their own policies. We use them only to fix problems.

3. Information stored on the device

To show progress, the app saves the following on the device only:

• for each practice session: the date and time, addition or subtraction, the chosen number, and the problem layout;
• for each problem: the problem, whether the answer was correct, how long it took, and the digit the app read (with how sure it was);
• the handwriting on the problem card, saved as strokes (position, timing, pen pressure, and whether a pen or a finger was used) so it can be replayed;
• your settings: time per problem, problems per session, writing input, and how long to keep history;
• which parts of the first-run guide have been shown, and whether the purchase has been made (so the unlocked parts also work offline).

When you tap the button that turns the screen, the app briefly reads the motion sensor (accelerometer) to tell how the device is being held. These readings are used at that moment only and are not saved.

4. Handwriting recognition

The app reads handwritten digits with a small recognition model that is built into the app and runs on the device. Your child’s handwriting is never uploaded, and we never receive it.

5. Third-party services

The app includes no third-party services that collect data. It is built with Flutter, Google’s open-source app framework, and four open-source plugins. Two work only on the device: path_provider finds the app’s storage folder, and sensors_plus reads the motion sensor. in_app_purchase connects to the App Store or Google Play for the purchase, and url_launcher opens this policy in your web browser.

The App Store and Google Play handle downloading and updating the app, and the purchase, under their own policies: Apple Privacy Policy · Google Privacy Policy.

6. Purchases

The app is free to download and offers one optional, one-time purchase that unlocks the numbers 10 to 19 and the test. There are no subscriptions. The App Store or Google Play handles the payment and tells the app whether the purchase was made; we never see payment details, and the app sends nothing about the purchase to us. The app notes on the device that the purchase was made, so the unlocked parts work offline, and each time it starts it asks the store what has been bought, so a reinstalled app unlocks by itself. The purchase screen opens only after the grown-ups check described in section 7. Apple and Google give us sales reports under their own policies.

7. Children’s privacy

Plus & Minus is made for children. We do not collect personal information from anyone, including children under 13, the age covered by the U.S. Children’s Online Privacy Protection Act (COPPA). Because the app has no ads, analytics, or accounts and sends nothing to us, nothing a child does in the app is shared with us or with anyone else. The purchase, the link to this policy, erasing history, and changing how long it is kept are behind a grown-ups check (a two-digit × one-digit multiplication question), so a young child can’t reach them by accident. Parents can review the history in the app and delete it at any time (section 8).

8. Retention and deletion

History stays on the device until it is deleted: automatically after the period chosen in Keep history (if you choose one), all at once with Erase history in Settings, or when the app is deleted. Changing Keep history and using Erase history both ask a grown-up first. We have no copy to keep or delete. Device backups to iCloud, a computer, or a Google account may include the app’s data; those are managed by you and by Apple or Google.

9. Your rights and choices

You control all of the app’s data on the device, as described above. Because we don’t collect or hold personal information, there is nothing on our side to access, correct, or delete, but you can contact us about any privacy question or request at support@innomote.com, and we will respond.

10. Changes to this policy

If we change how the app handles information (for example, by adding a feature that uses the internet), we will update this page and its effective date before the change is released.

11. Contact

Innomote LLC · support@innomote.com