Privacy Policy
Effective date: September 11, 2026
Last updated: September 11, 2026
Yomoe Studio ("we", "us") sets out below how information is handled in "Yomoe Math" (the "App"), a math learning application for children that we provide. The App is designed mainly for children aged 3 to 10. We ask parents and guardians to read this policy before letting a child use the App.
1. Basic policy
The App requires no user registration (no account) and does not ask children or parents to enter a name, email address, date of birth, or any other information that identifies a person. All questions are created on the device, and neither learning activity nor learning records are sent to or stored on our servers. Learning features — solving questions, progressing through levels and viewing records — work without a network connection.
2. Information stored only on the device
The following information created and recorded by the App is stored only in the App's private storage area on the device, and we never obtain it.
(1) Learning progress: progress in each practice course, stars earned in Adventure and best records for timed levels, Daily Challenge completion and streak
(2) Learning records: questions answered, correct answers and time spent per day, accuracy per operation, session history (start and end time, content, accuracy), questions in the Review Book, badges earned, best combo
(3) Settings and management information: display language, purchase status, first launch time and total learning time (used to manage how often ads appear), information used to manage review prompts, and whether notification permission has already been requested
This information is used only to resume learning, to compile and display records (including in Parent Mode), to evaluate badges, and to manage how often ads and review prompts appear.
2-2. Information sent to our servers (feedback)
The App's "Feedback" feature is available only from the Settings screen, which is behind a parent check (a math question). Only when a parent enters a message and sends it is the following information sent to and stored on our servers. The App does not otherwise transmit learning activity to us.
(1) Category (bug report / suggestion)
(2) The text of the feedback
(3) Email address (optional; you can send without it)
(4) Environment information: package name, app version, device model name, OS version (sent blank if it cannot be obtained)
We use this information only to investigate problems, to improve the App, and to reply if an email address was provided. We do not use it for advertising or any other purpose, and we do not provide it to third parties except as required by law. Please do not include personal information you do not wish to disclose, such as your child's name or school, in the feedback text.
3. Access to device features
The App does not request access to the camera, photo library, microphone, contacts, location (GPS), or files.
Note that on iOS, as required by Apple, the App's information declares a purpose for "location (while in use)" because an SDK used for advertising may reference that capability. The App itself never asks for location permission and never obtains or uses location.
The App asks for permission to send notifications. They are used only for practice reminders on the device when the App has not been opened for a while (3, 10 and 24 days). They are composed entirely on the device — they are not push notifications from a server, and no information is transmitted for them. If permission is declined, the reminders simply do not appear; everything else works exactly the same. This can be changed at any time in the device settings.
4. Third-party services
The App uses the third-party services below. Their handling of information is governed by each company's own privacy policy.
(1) Google AdMob (advertising)
The App displays ads so that it can be offered free of charge. Because the App is intended for children, every ad request is sent with child-directed treatment (treatment as child-directed under the U.S. Children's Online Privacy Protection Act (COPPA), and as under the age of consent in the European Economic Area and similar regions), and ad content is limited to content suitable for all ages (G).
- As a result, no personalized (interest-based) ads or remarketing ads are served.
- The App does not use advertising identifiers (IDFA on iOS, advertising ID on Android). The App does not show the iOS tracking permission dialog.
- For ad delivery, measurement and fraud prevention, device information, approximate location (region derived from IP address), and information about ad impressions and interactions may be collected and used by Google LLC.
- In the European Economic Area, the UK and Switzerland, Google's consent management is used with users treated as under the age of consent. Where required, it can be reviewed and changed from "Ad & Privacy Settings" on the Settings screen.
- Ads appear only at the bottom of the home screen and after a round of questions is finished, never while questions are being answered.
- If the Pro version described below is purchased, no ads are shown and no information is collected for ad delivery.
Google Privacy Policy: https://policies.google.com/privacy
How Google uses data in advertising: https://policies.google.com/technologies/partner-sites
(2) Apple App Store / Google Play (in-app purchase)
The "Pro version" (no ads) is purchased from the Settings screen, behind the parent check, through the billing platform provided by Apple Inc. or Google LLC. Payment information such as credit card numbers is never provided to us and we never hold it. All we refer to is whether a purchase exists.
(3) Retrieval of app configuration
On launch and when returning to the App, the App communicates with our server (https://api.yomoestudio.com) to retrieve configuration such as the required app version. This communication sends no learning activity and nothing that identifies a person. By the nature of network communication, the IP address and time of the request are recorded in the server access log; we use these only to prevent unauthorized access and to respond to incidents.
(4) Displaying this policy and the Terms of Use
When this policy or the Terms of Use are opened from the Settings screen, a page on our website (https://yomoestudio.com) is displayed. This screen does not open pages outside our website. The IP address and similar information may be recorded in the web server access log when the page is displayed.
(5) Store review feature
Review prompts use the standard features provided by Apple and Google. Review content is sent to the respective store, and we cannot link a review to an individual user.
5. Provision to third parties
Except as described in the preceding section, we do not provide information to third parties. This does not apply where disclosure is required by law.
6. Deleting data
Uninstalling the App deletes all data from the device, including learning progress, records, and settings. Because we do not hold learning data, there is no need to request deletion of learning data from us. If you would like information sent as feedback to be deleted, please contact us at the address below.
7. Children's privacy
(1) The App does not collect names, contact details, or any other information that identifies a child.
(2) Purchases, sending feedback, opening the store review page or web pages, and ad and privacy settings are grouped on the Settings screen behind a parent check (a math question), so that children are unlikely to use them by mistake. Opening the store when an update is required is also behind the parent check.
(3) As described in 4.(1), ads are served with child-directed settings and without advertising identifiers.
(4) If we learn that we have unintentionally obtained personal information from a child, we will delete it promptly. If you notice anything, please contact us at the address below.
8. Your rights (GDPR / CCPA and similar)
Learning data exists only on the device and we do not hold it. The rights of access and erasure can therefore be exercised directly on the device (including deletion by uninstalling). For information sent as feedback, please contact us at the address below. We do not sell personal information. Regarding the exercise of rights concerning data handled by advertising providers, please refer to the links in 4.(1) above.
9. Security
Because learning data is stored on the device, its security depends on the security of the device itself (screen lock, OS updates, and so on). Please manage the device appropriately. Information sent to our servers is kept with access restrictions in place.
10. Language of this policy
The Japanese version of this policy is the authoritative text. We may provide translations into English and other languages for convenience, but these are provided for reference only. In the event of any discrepancy or difference in interpretation between the Japanese version and a translation, the Japanese version prevails.
11. Changes to this policy
We may change this policy as necessary. If we make a material change, we will give notice within the App or through the app store. Continued use of the App after a change is deemed agreement to the changed policy.
12. Contact
For inquiries about this policy, please contact us at:
Yomoe Studio
contact@yomoestudio.com