Privacy Policy

This Privacy Policy explains what personal data the JLPT Master app (the "App") collects, how we use it, and the choices and rights you have. The App is operated by an individual developer based in Japan under the Nihongo Club Sakura brand. We act as the data controller for the personal data described here. You can contact us about privacy at any time at nihongoclubsakura@gmail.com.

This Policy is a notice about our data practices. Where applicable law requires consent, including for personalized advertising or tracking, we ask for that consent separately.

1. Who this applies to

The App is intended only for users aged 18 and older. After sign-in and before using the App, we ask users to confirm that they are at least 18. We store that confirmation with the versions of the Terms and Privacy Policy accepted and the server-recorded time; we do not ask for or store a date of birth.

We do not knowingly collect personal data from anyone under 18. If we learn that an account belongs to a person under 18, we will disable the account and delete their personal data, subject to any records we must retain by law. If you believe a person under 18 has provided us data, contact us at the address above.

2. What we collect

Information you provide:

Account details — your email address, display name, sign-in provider (Google, email/password, or Apple on iOS), account identifiers, preferred JLPT level, locale, and timezone.
Support and feedback — the content of question reports, abuse reports, or emails you send us.

Information created as you use the App:

Study activity — your practice and mock-exam attempts, answers, skipped questions, timing, scores, JLPT-style scaled score estimates, level estimates, pass estimates, progress, streaks, XP, badges, mock-exam credits, and other in-app rewards.
Purchase data — your subscription and entitlement status, product IDs, transaction identifiers (an Apple original transaction ID or a Google Play purchase token), and receipt or transaction verification data. Payment card details are handled by the store that billed you — Apple or Google — never by us; we receive only confirmation of your purchase and its status. To link a purchase to your account we send the store a pseudonymous identifier for your in-app account (Apple appAccountToken, Google obfuscatedAccountId); it contains no name, email, or other directly identifying data.
Advertising choices and events — ad consent choices, privacy-options status, advertising identifiers when permitted, ad interactions, and rewarded-ad completion events needed to grant in-app rewards.

Flashcards (on your device only):

Flashcard decks and cards — decks you create or import, cards, review history, scheduling, and attached media are stored locally on your device. We do not upload this content to our servers and cannot access it. The in-app "Export my data" option covers the account and study records we store, not on-device flashcards.

Information collected automatically:

Device, network, and diagnostics — including IP address, request metadata, app version, operating system, device identifiers, advertising identifiers when permitted, and error or diagnostic information used for advertising, security, fraud prevention, and keeping the service working. The advertising identifier is the Apple Identifier for Advertisers (IDFA) on iOS, or the Google Advertising ID (AAID) on Android. On iOS, access to the IDFA is requested through Apple's App Tracking Transparency prompt. On Android there is no such prompt; the AAID is governed by your Google consent choices and by the Android system settings described in Section 4.
Product analytics — aggregated in-app usage such as which screens and tabs you open and which features you use, recorded via Google Analytics for Firebase. We use this to understand how the App is used and to improve it. These events use a pseudonymous app-instance identifier; they are not tied to your name or email and are not used to identify you as a person. We do not send flashcard card contents. We configure Analytics without the advertising identifier.

3. How we use your data

We use personal data to:

create and operate your account and sign you in;
provide the study features, grade attempts, and show your progress and analytics;
process and manage subscriptions and entitlements;
show advertising in the free tier (with your consent where required);
grant and manage in-app rewards, XP, badges, and credits;
respond to support requests and handle question/abuse reports;
measure, debug, secure, and improve the App;
keep the App secure, prevent abuse, and comply with legal obligations.

Legal bases (EU/UK GDPR): we rely on performance of our contract with you (to provide the App), your consent (for personalized advertising and tracking), our legitimate interests (to secure and improve the service), and compliance with legal obligations.

4. Advertising and tracking

The free tier shows ads served by Google AdMob. AdMob may process data such as device identifiers, IP address, coarse location inferred from IP address, app activity, and ad interactions to serve ads, measure ads, prevent fraud, and, where you consent, personalize ads.

Where required by law (for example in the EEA, UK, and Switzerland), we use Google's User Messaging Platform (UMP) to ask whether you agree to personalized advertising. The same mechanism presents the opt-out required in US states that grant one. UMP runs on both iOS and Android. On iOS we additionally use Apple's App Tracking Transparency prompt before any cross-app tracking or access to the advertising identifier; Android has no equivalent prompt.

If you decline or withdraw consent, you may still see contextual or non-personalized ads. You can change or withdraw your choice at any time:

In the App — the ad privacy options in the Privacy Center, shown wherever your region requires them.
On iOS — Settings → Privacy & Security → Tracking.
On Android — Settings → Google → All services → Ads, where you can reset or delete your advertising ID.

Removing ads is also a benefit of a premium subscription.

We do not sell your personal data for money. We share personal data only as needed to run, secure, monetize, and improve the App, including with:

Google Firebase and Google Sign-In — authentication, hosting of the public legal pages, and Google Analytics for Firebase (product analytics as described in Section 2);
Google AdMob — advertising, including the User Messaging Platform consent and opt-out forms;
Google Play — app distribution on Android, Google Play Billing, purchase and refund processing, and real-time subscription-status notifications;
Apple — app distribution on iOS, Sign in with Apple, StoreKit, App Store purchase processing, refunds, and subscription-status updates;
Cloudflare — hosting, account and study-data storage (Workers, D1 database, KV, R2).

We may also disclose data where required by law or to protect our rights and the safety of users.

6. International transfers

Your data may be processed in countries other than where you live, including where our service providers operate. Where we transfer data internationally, we rely on appropriate safeguards (such as standard contractual clauses) as required by applicable law.

7. How long we keep data

We keep your personal data for as long as your account is active and as needed to provide the App. When you delete your account, we delete or de-identify your associated account and study data from active systems, except where we need to retain limited records for legal, tax, security, fraud-prevention, chargeback/refund, dispute-resolution, or compliance purposes. Retained records may include legal acceptance history, deletion-request audit records, subscription and transaction records, abuse/security logs, and backup copies until they are overwritten in the ordinary course. Where practical, retained records are minimized, hashed, or pseudonymized. Flashcard data that stays only on your device is not retained by us, because we never receive it. Deleting your account does not by itself erase flashcards still stored on the device.

8. Your rights and choices

Depending on where you live, you may have the right to:

access the data we hold about you and receive a copy (the App provides a self-service "Export my data" option for records we store; on-device flashcards are not included);
delete your account and associated data (self-service "Delete my account" option in the Privacy Center, or by emailing us — see Section 11);
correct inaccurate data;
object to or restrict certain processing, and withdraw consent to advertising/tracking at any time;
lodge a complaint with your local data-protection authority.

California residents (CCPA/CPRA): you have rights to know, delete, and correct your personal information, and to opt out of "sharing" for cross-context behavioral advertising. We do not sell your personal information for money. To the extent Google AdMob personalized advertising is considered "sharing" under California law, you can opt out through the in-app ad privacy choices where shown, through your device settings (iOS tracking settings, or the Android ads settings described in Section 4), or by contacting us. Exercise other rights using the in-app export/delete tools or by emailing us. Residents of other US states with comparable laws have equivalent opt-out choices through the same controls.

To exercise any right, use the in-app tools or email nihongoclubsakura@gmail.com. We will respond within the time required by applicable law and will not discriminate against you for exercising your rights.

9. Security

We use reasonable technical and organizational measures to protect your data. No method of transmission or storage is completely secure, so we cannot guarantee absolute security.

10. Changes to this Policy

We may update this Policy from time to time. When we make material changes, we will update the version and "last updated" date and, where appropriate, ask you to review and accept the updated Policy in the App.

11. Contact

For any privacy question or request, email us at nihongoclubsakura@gmail.com.

Last updated: September 3, 2026 · Version 2026-09-03.1