Privacy Policy

Overview

KikuPuku is an iOS app for learning Japanese vocabulary, operated by KOALA STACK DIGITAL (ABN 39194545109) ("we", "us", or "our"). This Privacy Policy explains what information we collect, how we use it, and the choices available to you. KikuPuku requires an active subscription (or trial) to use the app. Access to the app is handled through Sign in with Apple or Google.

Information We Collect

Account information. When you sign in, your chosen provider (Apple or Google) may share basic account details such as your name and email address. We receive an account identifier from our authentication service (Supabase) so we can associate your activity with your account. We do not offer email-and-password sign-in.

Vocabulary and learning data. As you use KikuPuku, you create learning data on your device, including saved words, meanings, example sentences, spaced-repetition review history, decks, review sessions, handwriting practice progress, app preferences (such as your daily review goal and flashcard settings), and usage statistics like streaks and words remembered.

Photos and audio. If you use Photo capture, images you take or import are stored on your device. To recognise Japanese text in a photo, the image is sent to our servers for processing. If you use Listen, audio you record is sent to our servers for transcription and enrichment. Photo files and audio files themselves are not uploaded to cloud backup — only on-device metadata and processed results (such as recognised text or transcripts) may be included in a backup.

Server-processed requests. Several features send data to our servers for processing, including: word search and AI suggestions; word enrichment (meanings, example sentences, and cultural notes); text-to-speech playback; photo text recognition; and audio transcription. These requests are authenticated to your account and subject to daily rate limits.

Cloud backup. If you use Cloud Backup (a subscriber feature), you can manually save a compressed copy of selected learning data to our cloud storage. A backup includes vocabulary, review progress, decks, completed sessions, photo OCR results, recording transcripts, handwriting practice data, and certain preferences. It does not include photo JPEGs, audio recordings, or notification settings.

Leaderboard (optional). If you choose to join the global leaderboard, you select a public display name (handle) and we store that handle together with your count of words remembered. You can change your handle or leave the leaderboard at any time from the app.

Community library. When you search for or save words, we may store normalised word entries and enrichment results on our servers to improve lookups for all users. This data is keyed by word readings and meanings, not by personal content you type elsewhere in the app.

Subscription status. We use RevenueCat and Apple's App Store to manage subscriptions. We receive information about whether your subscription or trial is active, but we do not receive or store your payment card details — those are handled entirely by Apple.

Analytics and diagnostics. We use PostHog to understand how the app is used (for example, which features are opened, review sessions completed, and words saved). Analytics is linked to your account identifier, not your name or email. You can turn analytics off in Account settings. We use Sentry to collect crash reports and error diagnostics to keep the app stable. Sentry is disabled during development builds.

Notifications. KikuPuku schedules review reminders locally on your device using Apple's notification system. We do not collect push notification tokens or run a notification server.

How We Use Information

We use the information described above to provide and maintain KikuPuku's core features: saving and reviewing vocabulary, capturing words from text search, photos, and audio, tracking your learning progress, optional cloud backup and restore, optional leaderboard participation, and subscription access. We use analytics and error reports in aggregate or pseudonymous form to understand usage patterns, measure feature performance, and fix bugs. We do not sell your personal information.

How Your Data Is Stored

KikuPuku is built as a local-first app. Your vocabulary, review history, photos, recordings, and most other learning data are stored primarily in a database on your iPhone. Network features process specific requests on our servers and return results to your device; they do not replace your on-device database as the primary store.

Cloud Backup is optional and manual — it does not continuously sync your data in the background. You choose when to save or restore a backup. Backups are stored in Supabase Storage and are tied to your account.

Third-Party Services

KikuPuku relies on trusted third-party services to operate. These providers process data on our behalf to deliver specific features:

• Supabase — authentication, server infrastructure, edge functions, and cloud backup storage
• Apple — Sign in with Apple, App Store subscription billing, and local notifications
• Google — Sign in with Google, Cloud Vision (photo text recognition), and Cloud Text-to-Speech (word pronunciation)
• RevenueCat — subscription and entitlement management
• Superwall — in-app paywall presentation
• PostHog — product analytics
• Sentry — crash and error reporting
• AssemblyAI — audio transcription for the Listen feature
• AI service providers — word suggestions, enrichment, transcript processing, and related language tasks (accessed through our servers, not directly from the app)

These providers are permitted to process data only as needed to deliver their service to us. We select providers with appropriate security practices, but their handling of data is also governed by their own privacy policies.

Your Choices

Analytics. You can disable product analytics at any time in Account → Settings. Sentry error reporting is not individually opt-outable, but it does not include your vocabulary content.

Leaderboard. Joining the leaderboard is entirely optional. You can leave or change your display name from the app at any time.

Cloud backup. Using cloud backup is optional. Your learning data remains on your device whether or not you create a backup.

Notifications. You can enable or disable review reminders and control their timing in Account settings. All notification scheduling happens on your device.

Account deletion. You can delete your account from Account → Delete Account. This permanently removes your authentication account, cloud backup (if any), leaderboard entry, and server-side records associated with your account. Your local data on the device is also deleted as part of this process. Account deletion cannot be undone.

Children's Privacy

KikuPuku is not directed at children under the age of 13, and we do not knowingly collect personal information from children under 13. If you believe a child has provided us with personal information, please contact us so we can address it.

Changes to This Policy

We may update this Privacy Policy from time to time to reflect changes in our practices or for legal or operational reasons. We will update the "Last updated" date at the top of this page when we make changes. Continued use of KikuPuku after an update constitutes acceptance of the revised policy.

Contact

If you have questions about this Privacy Policy or how your information is handled, contact us:

KOALA STACK DIGITAL
506 Kenilworth Skyring Creek Rd
Ridgewood QLD 4563
Australia
Phone: +61 478 944 736
Email: support@koalastack.com