QuadTalk Privacy Policy
Amendment announced November 3, 2026 · effective November 10, 2026 (first effective October 18, 2026)
This is a translation. The Korean original is the official version; if the two differ, the Korean original prevails.
TerryWi (the "Provider") establishes and publishes this Privacy Policy in accordance with Article 30 of the Korean Personal Information Protection Act, to protect users' personal information and to handle related concerns promptly. QuadTalk is a language-learning app in which you pick one of Korean, English, Japanese and Chinese as your base language and learn the other three together. As a rule, your learning records are stored only on your device.
Article 1 (Purposes of collection and use)
The Provider processes the minimum personal information needed for the purposes below. It is not used for any other purpose; if a purpose changes, the Provider will take the necessary steps, such as obtaining separate consent.
- Core features: Lessons, practice and review, bosses (level-up tests), bonuses, Word Book and Vocab Island, the study calendar and statistics of QuadTalk (the "Service"), and your progress in them, are stored only on your device. The Provider collects or keeps no personal information for this purpose.
- Study reminder: A once-a-day study reminder at the time you choose is scheduled and shown on your device. Nothing is sent off the device.
- Backup and restore (optional): By connecting a Google account, you can back up your learning records to your own Google Drive and restore them.
- Speaking practice (optional): in the Speak step of a lesson, when you tap "Speak", what you say in that language is turned into text, shown on screen, and compared with the sentence.
- Advertising: Ads (banner, interstitial and rewarded) are shown through Google AdMob to fund the Service.
- Paid subscription (optional): Payment for the QuadTalk Plus subscription and checking its status are handled by the Google Play billing system.
Article 2 (Information collected and how)
Items collected
- [Optional, when you connect an account] Google account information: email address (or display name). After you connect your Google account (OAuth), it is obtained from Google Drive and used only to show the connected account on screen; it is stored only on your device. All learning features work without connecting an account; it is needed only for Google Drive backup and restore.
- [Created while you use the app, stored locally] Settings and learning records: app settings such as base language, birth year, daily goal, pronunciation hint level and reminder settings, and progress such as completed units, stars, test results, streak, study calendar, review cards and number of words learned. This stays in your device's storage and is not sent to the Provider (the Provider runs no server of its own).
- [When you use backup] Google Drive backup data: each time you tap "Back up now", the settings and learning records above are saved as JSON in the app-only space (appDataFolder) of your own Google Drive. The app never backs up automatically. This area is private — even you cannot open it in the Google Drive screens — and no third party, including the Provider, can access it. The Service does not look at your other Drive files.
- [Optional, when you use Speak] Voice: the app listens only after you tap "Speak", while you are speaking. The device's speech recognition service (for example, Google) turns your voice into text and may send the audio to its own servers to do so. QuadTalk does not store or send your voice, and it only shows the resulting text on screen without saving it.
- [Collected automatically by the ad SDK] Advertising ID and device information: the Service shows ads (banner, interstitial and rewarded) through Google AdMob, during which Google may collect the advertising ID, IP address (to estimate approximate location), device information and diagnostic data about ad impressions and clicks. The Provider does not collect or keep this itself; it is handled under Google's privacy policy.
- [When subscribing, optional] Subscription status: Payment is handled by Google Play, and the Provider does not receive payment details such as your name or card number. The app only checks with Google Play whether the Google account on the device subscribes to QuadTalk Plus, and stores the result (subscribed or not) only on your device.
How it is collected: your own input while using the Service, Google account connection (OAuth), and automatic collection by the ad SDK. Apart from the microphone in the Speak step, the Service does not access your contacts, messages, call logs, location, photos or other personal data on the device.
Reading sentences aloud: the device's text-to-speech (TTS) is used to play learning sentences. Only the learning sentences built into the app are passed to it; no personal information is included.
Article 3 (Retention period)
- Google account information: deleted from the device immediately when you run "Sign out" or "Disconnect account and delete backups".
- Records stored on the device: deleted from the device as soon as you uninstall the app. Nothing is kept on a Provider server. The Service excludes its data from Android device backup and device-to-device transfer.
- Google Drive backups: up to the 3 most recent backups are kept in your own Drive. When a new backup makes more than 3, the oldest is deleted. You can delete backups one by one in the "Restore from Drive" list; "Disconnect account and delete backups" deletes all of them immediately; "Sign out" alone leaves them so you can reconnect and restore.
- Voice: QuadTalk keeps none. Audio processed by the device's speech recognition service is subject to that provider's policies.
- Advertising ID and diagnostic data: subject to Google's policies and retention periods.
- Subscription status: the subscribed-or-not value stored on the device is deleted when the app is uninstalled. Google Play purchase and payment records follow Google's policies and the retention periods required by law.
Article 4 (Destruction procedure and method)
- Procedure: when you run "Sign out", "Disconnect account and delete backups" or delete a single backup in the app, or uninstall the app, it is processed immediately without any approval step.
- Method: local data is deleted from device storage; Google Drive backup files are deleted through the Google Drive API so that they cannot be recovered.
Article 5 (Your rights and how to exercise them)
You can exercise the following rights yourself in the app at any time.
- Delete one Drive backup (Passport > Account · Backup > Restore from Drive > Delete): deletes only the backup you choose
- Delete all Drive backups (Passport > Account · Backup > "Disconnect account and delete backups"): deletes every backup file in Google Drive, revokes the Drive permission given to the app, and disconnects the account
- Sign out (Passport > Account · Backup > Sign out): deletes only the account connection (Drive backups and learning records on the device stay)
- Turn off reminders / revoke permission: turn them off in Passport > Notifications or revoke the notification permission in system settings (only reminders stop; learning features keep working)
- Revoke microphone permission: in system settings at any time (only the Speak button stops working; everything else keeps working)
- Uninstall the app: all settings and learning records stored on the device are deleted with it
For any other privacy questions, contact wwwtaekyu@gmail.com; the Provider will act without delay.
Article 5-2 (Children's privacy)
The Service can be used by people of all ages, including elementary school children. On first launch it asks for the year of birth, and for users who are, or may be, under 14 (judged from the birth year alone, so it includes some 14-year-olds; the same applies before a birth year is chosen; "child users"), the Service works as follows:
- Account connection and Drive backup are not offered. The Provider therefore does not process child users' email or other account information, and does not collect personal information that requires parental consent.
- Ads are requested as child-directed. Requests to Google AdMob are tagged as child-directed and under the age of consent, and only ads rated G (general audiences) are accepted. Personalized ads are not shown, and Google limits the use of the advertising ID and similar information under its own policies for child-directed requests.
- The birth year is stored only on the device and is never sent anywhere.
- Speak (speech recognition) is available to child users too. The voice is processed by the device's speech recognition service; the Provider receives neither the audio nor the text. Parents can turn off the microphone permission in the phone's settings.
Parents or legal guardians may contact us by email about a child user's personal information. Note that the Provider keeps no separate copy of child users' data; uninstalling the app removes everything on the device.
Article 6 (Security measures)
- Technical: settings and learning records are stored locally on the device and are not sent anywhere unless you run a Drive backup. Google account authentication uses Google's standard OAuth, and communication with Google Drive is encrypted with TLS. Backups are stored in the app-only private area (appDataFolder) of your own Drive. Backups are not end-to-end encrypted; they rely on your Google account's security.
- Administrative: the number of people handling personal information is kept to a minimum.
Article 7 (Processors and third parties)
The Provider runs no server of its own to keep your learning data. The services below are used for the purposes listed; information processed by each is subject to that company's privacy policy.
| Purpose | Service | Information |
|---|
| Account connection | Google account authorization (Google LLC) | Email, account identifier |
| Backup and restore of learning records | Google Drive API — appDataFolder (Google LLC) | Settings and learning records |
| Advertising | Google AdMob (Google LLC) | Advertising ID, IP address, device information, diagnostic data |
| Subscription payment (only when used) | Google Play billing system (Google LLC) | Purchase records, subscription status (payment details handled by Google) |
| Speak (only when used) | The device's speech recognition service chosen in device settings (usually Google LLC) | Voice spoken during Speak |
Google Privacy Policy: https://policies.google.com/privacy
Article 8 (App permissions)
The Service uses the following permissions only for the purposes stated.
- Notifications (POST_NOTIFICATIONS): only to show the study reminder you turned on. Requested during first-time setup or in reminder settings; everything except reminders works without it.
- Receive boot completed (RECEIVE_BOOT_COMPLETED): only to reschedule the study reminder after the device restarts.
- Internet (INTERNET): only for Google account connection, Google Drive backup and restore, and ads.
- Microphone (RECORD_AUDIO, optional): only for the Speak step of a lesson. Requested the first time you tap "Speak"; the app listens only after you tap it, while you speak. Everything except Speak works without it.
- Advertising ID (AD_ID): used by the ad SDK to serve and measure ads.
- Billing (BILLING): used only to subscribe to QuadTalk Plus through Google Play billing and to check the subscription status.
The Service does not request access to SMS, contacts, call logs, location, photos or files.
Article 9 (Advertising)
The Service shows banner, interstitial and rewarded ads through Google AdMob to users who do not subscribe to QuadTalk Plus. Rewarded ads are watched only when the user chooses. Information such as the advertising ID may be collected for ad personalization; you can opt out of ad personalization or reset or delete your advertising ID in your device settings (Settings > Privacy > Ads). As a family app, it requests only ads rated G (general audiences) for all users; child users are also covered by Article 5-2. In regions where separate consent is required, such as the EEA, the UK and Switzerland, a consent flow is shown through Google's User Messaging Platform (UMP), and the ad SDK is not initialized before consent.
Article 10 (Privacy officer)
- Provider: TerryWi
- Privacy officer: TerryWi (owner)
- Contact email: wwwtaekyu@gmail.com
You may contact the privacy officer about any privacy-related inquiry, complaint or remedy arising from your use of QuadTalk.
Article 11 (Changes to this policy)
This Privacy Policy applies from November 10, 2026 (first effective October 18, 2026). Any additions, deletions or changes will be announced in the Service or in this document at least 7 days before they take effect.
The Korean text is the original; English, Japanese and Simplified Chinese translations are published for convenience. If a translation differs from the original, the Korean original prevails.
First announced and effective: October 18, 2026
Amendment announced: November 3, 2026 · effective: November 10, 2026 (paid subscription and billing permission, interstitial and rewarded ads, Word Book and Vocab Island)
Contact: wwwtaekyu@gmail.com