Rabbit Lingo Privacy Policy

Version 2　　Last updated: 2026-10-26　　Effective: 2026-10-26

Rabbit Lingo (the "App") is provided by Mossbun Labs ("we", "us"). We process personal information lawfully, fairly, only to the extent necessary, in good faith and transparently, in accordance with applicable data protection laws, including the Personal Information Protection Law of the People's Republic of China and, where applicable, the EU and UK General Data Protection Regulation.

This Policy applies to the Windows and Android versions of the App. Please read it carefully before using the App, in particular the provisions in bold. By tapping "Agree" you confirm that you have read and accept this Policy, including that your learning data and the text you send to AI are stored and processed on servers in Singapore (see Section 3).

1. Information we collect and how we use it

1.1 Before you agree to this Policy

Until you agree to this Policy, the App does not connect to the internet, does not synchronize, does not initialize any analytics or error-reporting component, and does not record usage data. If you choose "Browse only", you may consult the built-in dictionaries and sample content on your device; the App still does not connect to the internet and does not save your lookup history.

1.2 Account

To provide cross-device sync, AI allowance and subscriptions, you may sign in with a one-time code sent to your email address, or, on Android devices with Google services, with your Google account. We collect your email address and the account identifier returned by the sign-in provider. You may use the App on a single device without signing in, but sync, hosted AI and subscriptions will not be available.

You may optionally provide a nickname and an avatar, which are shown on your learning reports.

When you sign in, we record the name of the device used (the computer name or phone model) and the sign-in time, in order to show it under "Signed-in devices" and let you remove it.

1.3 Learning content

To provide its core features, the App stores on your device the content you provide or create while using it: imported reading materials, saved words and expressions with their source sentences, lookup history, practice answers and scores, learning reports, reading progress, and learning settings (interface language, native language, explanation language, self-described level and similar).

By default this content stays on your device. If you sign in and turn on sync, it is synchronized to your account so that your devices stay consistent. Android system backup does not back this content up to Google Drive; it moves to a new phone only when you use the system's device-to-device transfer from your old phone.

1.4 AI features

When you use AI features such as finding items, generating explanations, AI lookup, grading practice answers or analyzing reports, we send the text strictly needed for that request (for example the sentence or passage you selected, your answer, and the necessary settings and level information) to an AI service provider, and return the result to you. The text is relayed through our servers: to reduce latency, a request may first reach the server node nearest to you and is then passed on to our servers in Singapore; the text is not stored in this process. Our servers record only, for each call, the feature name, the model used, usage, cost, duration and outcome — not the text — and your account information is not sent to the AI service provider. We require AI service providers not to retain this text and not to use it to train models. The providers, their purposes and processing methods are listed in Appendix 2.

AI-generated content may be inaccurate and is provided for learning reference only. The App labels areas generated by AI, such as explanations, reports and feedback.

If you tap "Feedback" on AI-generated content and submit it, we store an excerpt of that content (up to 500 characters), the type of problem you selected and your additional note (up to 300 characters), the platform, the app version and the time of submission; if you are signed in, your account identifier is linked to it. These records are kept for one year and used to improve the quality of the content and to deal with inappropriate content; when you delete your account, the account identifier is removed from them.

1.5 Sync and backup

If you sign in and turn on sync, your learning content, learning settings and usage data are stored on our cloud servers under your account in order to synchronize your devices. The Windows version additionally keeps automatic backups on your computer.

To guard against data loss from a server failure, each day we export a backup of the account information and service records held on our servers (including email addresses and subscription and allowance records, but not the synchronized learning-content files themselves) to Cloudflare object storage, and delete each backup automatically after 30 days.

1.6 Usage data

To improve our learning algorithms and features, the App records how features are used, for example whether you expand related expressions after a lookup, the length of a text selection in the reader and the time from selection to lookup, the type chosen when importing material, and the duration and outcome of a sync. This data does not contain any text you type or read; it is recorded only as internal identifiers and numbers.

In addition, our servers record, per account: whether you opened the App on a given day and whether you practiced on a given day (dates only); hosted-AI call records (feature name, model, usage, cost, duration and outcome — no text); and the number and date of premium exports on the free plan. These records are used for allowance accounting, cost accounting, abuse prevention and statistics. Per-attempt AI records are kept for 35 days; the usage and cost ledger is kept, and after you delete your account its account identifiers no longer correspond to anyone.

Usage data is stored with your learning data on your device and, if sync is on, in your account. Individual records older than ninety days are aggregated into daily totals and then deleted. When you delete an item of learning content, identifiers in related records that point to it are replaced with random values, so the records can no longer be linked to that content.

We may use this data, after de-identification, for statistical analysis in order to study learning patterns and improve the algorithms and the service. We do not use it for advertising and we do not sell it to anyone.

1.7 Device information, region and error reports

To keep sync correct, the App generates a random identifier for each device.

To prevent invitation rewards from being claimed more than once, when you open the Invite friends page or enter an invitation code the App reads your device's system identifier (the machine identifier on Windows, the device identifier on Android), turns it on your device into an irreversible cryptographic digest, and sends only that digest to our servers; we keep the digest only and neither store nor can recover the identifier itself. On Android the App also reads, through Google Play's install referrer, the invitation code carried by an invitation link. We keep a record of the invitation: the invitation code, both account identifiers, a cryptographic digest of your email address, the digest of the device identifier and the reward status. To prevent a reward from being claimed again by deleting an account and registering anew, the digests of the email address and the device identifier are kept after you delete your account, but are no longer linked to any account.

To choose suitable AI service providers for your region and for statistics, our servers derive the country or region from the network address (IP address) of a request using a local lookup table and combine it with the system region reported by the App; only the two-letter country or region code is stored, not the IP address. IP geolocation data by DB-IP.com (https://db-ip.com). To diagnose faults, once you have agreed to this Policy the App may send, when an error occurs, the error type, the location in the program where it occurred, whether it caused a crash, the app version, the operating system type and version, and the device model to our own servers; no third-party error-reporting service is used. Error reports do not contain the error text, your learning content, your account or your device identifier; they are aggregated into daily counts and kept for 90 days. At start-up the App also reads a public configuration we publish (minimum version, feature switches, announcements), and the Windows version reads a version list from our download site; these requests carry none of your learning data.

1.8 Subscriptions and payments

Payments for Pro are handled by Google Play (Android) or the Microsoft Store (Windows). We do not collect your card or payment account details. On Android, subscriptions are verified and managed through RevenueCat: the App includes its software development kit, which at purchase submits your account identifier and the Google Play purchase credential to RevenueCat, and our servers also query RevenueCat for, and receive, your subscription status. On Windows, at purchase the App submits the purchase credential issued by the Microsoft Store to our servers; our servers query Microsoft for your subscription status and link your Microsoft account identifier to your account, so that one subscription cannot be used by several accounts. We receive and keep the subscription status, period, product, price and transaction identifier in order to provide the service.

1.9 Device permissions

The App requests the following permissions only for the related features; you may turn them off at any time in your system settings:

• ·Internet access (Android): for sync, AI features and dictionary downloads.
• ·Accessibility service (Android, optional): for Assist; only when you tap the floating button, the App reads the text you have selected on the current screen and looks it up. When no text can be read at that spot (for example text inside an image), the App captures one frame of the current screen and recognizes the text on your device with the Google ML Kit text recognition component, then discards the capture. The App does not continuously read your screen in the background. Other features work without this permission.
• ·Notifications (Android, optional): to tell you that a background task, such as AI processing, has finished.
• ·Reading selected text and screen-region capture (Windows): for Assist; while Assist is on, the App reads the text you select in other programs to tell whether it is English and look it up for you (depending on your settings, the card appears right after you select, or after you click the lookup icon). Password fields and programs you exclude in Settings are not read. Selected text is processed only on your computer unless you look it up further or collect it. When you drag to select a screen region, the App recognizes the text in that region, on your computer. To let you see where a word came from, the App also records the name of the program or the website domain the text came from.

1.10 Exceptions to consent

Where permitted by law, we may process personal information without your consent, including where necessary to conclude or perform a contract with you, to comply with legal obligations, to respond to public health emergencies or protect life, health or property in an emergency, or to process information you have made public, within a reasonable scope.

2. Entrusted processing, sharing, transfer and disclosure

We do not sell your personal information. To provide the features described in this Policy, we engage the service providers listed in Appendix 2 to process necessary information on our behalf. Our agreements require them to process it only for the purposes and in the manner we specify and to take appropriate security measures.

We do not otherwise share, transfer or publicly disclose your personal information, except with your separate consent; as required by law, legal process or competent authorities; or in a merger, division, dissolution or bankruptcy, in which case we will inform you of the recipient's name and contact details and require the recipient to continue to honor this Policy.

3. Cross-border transfers

Our cloud servers and some of our AI service providers are located outside the People's Republic of China. If you sign in and turn on sync, your account information, learning content and usage data are stored on servers in Singapore; when you use AI features, the related text is sent to the AI service providers listed in Appendix 2, some of which are located abroad. Daily backups of our servers are stored in Cloudflare object storage (Cloudflare, Inc., United States); when you buy a subscription, related information is sent to RevenueCat (United States) or Microsoft (United States).

Appendix 2 lists each overseas recipient's name, contact, purposes, processing methods and the types of personal information. You may exercise your rights against them through the contact in Section 9. By tapping "Agree" you acknowledge and accept the storage and processing described above; we do not ask for a separate consent. We rely on contractual necessity and appropriate safeguards such as standard contractual clauses (Section 7 and Appendix 2). You can withdraw your consent at any time in Settings › About: the App then works in browse-only mode, without network access or sync, and no longer transfers your personal information abroad; the learning content already on your device stays there.

If you are located outside China, your information may likewise be processed in Singapore, China and the United States. Where required, we rely on appropriate safeguards such as standard contractual clauses.

4. Storage and security

Location: learning content is stored on your device by default, and on servers in Singapore when sync is on.

Retention: we keep personal information only for as long as necessary for the purposes in this Policy. After you request deletion, your account is deactivated for 7 days, during which you can cancel by signing in again with the same email; afterwards we delete your account and all learning data synchronized to the cloud, completing this within 15 business days. Copies in the daily server backups are removed automatically as the backups rotate, within 30 days at most. The following are kept after deletion but can no longer be linked to you: the ledger of AI and subscription usage and cost, and the cryptographic digests of the email address and device identifier used to prevent repeated claims of invitation rewards, and any feedback on AI content you submitted (with the account identifier removed, kept for no more than one year). This does not apply where the law requires otherwise. Data on your devices remains under your control.

Security: data is encrypted in transit; cloud data is isolated per account and protected by access controls; only authorized personnel may access it, and only as needed. If a personal information security incident occurs, we will promptly inform you of the incident, its possible impact, the measures we have taken or will take and what you can do to protect yourself, and report to the authorities as required by law.

5. Your rights

• 1.Access and copy: you can view all of your learning content in the App and obtain a copy through Settings › Data › Export all data.
• 2.Correction: you can edit your learning content and profile directly in the App.
• 3.Deletion: you can delete any learning content in the App. On Windows you can also clear all learning data in Settings › Data; on Android you can delete learning content item by item or delete your account. "Clear / delete lookup history" only removes entries from the lookup list; it does not delete them (the App uses them to judge how familiar you are with words). Lookup history is deleted when you clear all learning data or delete your account.
• 4.Withdrawal of consent: you can withdraw your consent to this Policy (including the storage and processing described above) in Settings › About. We will then stop the related processing; processing carried out before the withdrawal is not affected.
• 5.Account deletion: you can delete your account in Settings › Account or through a web page we provide. Your cloud data is then deleted as described in Section 4.
• 6.Explanation and complaints: you can ask us to explain this Policy or file a complaint through the contact in Section 9.

We will respond within 15 business days after receiving your request and verifying your identity.

6. Minors

The App is intended for users of all ages. If you are under 14, please read this Policy together with your parent or guardian and use the App only with their consent. We process personal information of children under 14 only as necessary to provide the features described here; if we learn that we have done so without prior parental consent, we will delete it as soon as possible. Parents and guardians may contact us at the address in Section 9.

7. Users in the European Economic Area and the United Kingdom

If you are in the EEA or the UK, we process your personal information on the following legal bases: performance of our contract with you (account, sync, AI features, subscriptions); your consent (usage data, error reports); and our legitimate interests in improving the service, preventing abuse and fraud (repeated claims of invitation rewards), and keeping the service stable and its data safe (backups). You also have the rights to restrict processing, to object to processing and to data portability, and you may lodge a complaint with your local data protection authority.

8. Changes to this Policy

We may update this Policy. If a change concerns the purposes or methods of processing, the types of personal information or the recipients, we will notify you with a dialog the next time you open the App and will apply the new Policy only after you agree again. The current version is always available in Settings › About.

9. Contact us

If you have any questions, comments or complaints about this Policy or our processing of your personal information, please email us at [email protected].

Appendix 1 · Personal information we collect

Appendix 2 · Third parties we share information with (processors)

We will keep this list up to date as our service providers change (AI service providers may be adjusted by region).