Privacy Policy

Who we are

Sekana (“Sekana”, “we”, “us”, or “our”) is a mobile app for iOS and Android for learning kanji (application ID com.kxxn.sekana). It is an independent project, and we act as the controller of the limited data described below. If you have any questions about this policy or your data, contact us at support@sekana.app.

The short version

• Offline by default. All of your learning progress is stored locally on your device. You can use the entire app without an account and without an internet connection.
• Everything that leaves your device is opt-in. Cloud backup, diagnostics, and account sign-in are off until you turn them on.
• We show ads. Sekana displays occasional full-screen ads from Google AdMob. On iOS these use a tracking identifier only if you allow it.
• We never sell your personal data.

Data stored only on your device

By default, Sekana keeps everything on your device in a local database and never sends it to us. This includes:

• Your learning progress, such as your spaced-repetition schedule, mastery scores, XP, streaks, saved kanji, study, battle, and karuta decks, session history, and daily activity.
• Your preferences, such as display name, language, difficulty, sound, haptics, and reduced-motion settings.

This on-device data is not personal information we collect; it stays with you. You can erase it at any time from within the app (“Reset Progress”) or by uninstalling Sekana.

Camera and photos

Sekana can recognize a kanji from your camera or a photo you choose. This recognition happens entirely on your device. Images are processed locally to detect the character and are never uploaded, stored, or shared. The app asks for camera and photo-library permission only when you use this feature, and you can decline and still use the rest of the app.

Optional: creating an account

You can optionally sign in with Google or Apple to back up and restore your progress across devices. If you do, our authentication provider (Google Firebase Authentication) creates an account identifier for you, and the sign-in provider shares basic profile information such as your name and email address. With Sign in with Apple, you can choose Apple’s private email relay so we never see your real address. We use this only to identify your backup. You can use Sekana fully without ever signing in.

Optional: cloud backup & sync

If you turn on “Back up my progress”, a copy of your learning progress is stored in Google Firebase Firestore so you can restore it on a new device. This only happens while cloud sync is enabled and you are signed in. Your backup is saved to a private document keyed to your account and, per our security rules, is readable and writable only by you.

Your backup is stored in the European Union (Firestore region eur3). Turning off sync stops future backups, and resetting your local progress does not silently delete your cloud backup. You stay in control of deletion (see below).

Optional: diagnostics

To fix crashes and improve the app, Sekana can collect diagnostic data using Google Firebase. This is off by default and only starts if you enable “Share diagnostics” in the app. When enabled it includes:

• Crash reports (Firebase Crashlytics): crash and handled-error diagnostics, including device model, OS version, and app state at the time.
• Usage analytics (Firebase Analytics): anonymous usage events and screen views to understand which features are used.
• Performance (Firebase Performance): app performance traces such as start-up and screen render times.

You can turn diagnostics off again at any time, which stops further collection.

Advertising (Google AdMob)

Sekana shows occasional full-screen (interstitial) ads from Google AdMob at natural breaks, for example after a battle ends or when opening a kanji from search. We do not show banner ads. To serve and measure these ads, Google AdMob and its partners may process device information and advertising identifiers:

• On iOS, the advertising identifier (IDFA) is used only if you allow tracking in Apple’s App Tracking Transparency prompt. We also use Apple’s SKAdNetwork for privacy-preserving ad attribution.
• On Android, the Android Advertising ID may be used, subject to your device settings and consent.

Before serving ads in regions that require it (such as the EEA and UK under GDPR, and applicable US states), we present a consent form through Google’s User Messaging Platform. You can decline personalized ads or tracking and still use every feature of Sekana; you may then see non-personalized ads. You can learn more about how Google uses data from apps that use its services on Google’s website.

Location

Sekana itself does not collect or use your location. With your consent, our advertising partners (Google AdMob and its partners) may use approximate or precise location to show more relevant ads. You can decline this in the consent prompt and when iOS asks about tracking, and Sekana keeps working fully either way.

Notifications

Sekana can send optional reminders, for example review reminders. These notifications are scheduled locally on your device. There is no push server and no notification token is sent to us or to any third party.

Who we share data with

We do not sell your personal data. The optional features above rely on the following service providers, who process data on our behalf or as independent controllers under their own policies:

• Google: Firebase Authentication, Firestore, Crashlytics, Analytics, Performance, and AdMob (Firebase privacy, Google Privacy Policy).
• Apple: if you use Sign in with Apple (Apple Privacy Policy).

Where your data is stored & international transfers

Any progress you choose to back up is stored on Google’s infrastructure in the European Union. Diagnostics and advertising data are processed by Google on its global infrastructure. If you use Sekana from outside these regions, your data may be transferred to and processed in them under the safeguards used by Google.

How long we keep data, and how to delete it

• On-device data stays until you remove it with “Reset Progress” or by uninstalling the app.
• Account & cloud backup: you can delete your account and cloud data at any time. See our Account & Data Deletion page for the exact steps and what gets removed.
• Diagnostics & advertising data are retained by Google according to their retention policies.

Your privacy rights (EEA / UK)

If you are in the European Economic Area or the United Kingdom, you have the right to access, correct, delete, restrict, or object to the processing of your personal data, the right to data portability, and the right to withdraw consent at any time. Our legal basis for optional, opt-in features is your consent; for showing ads that keep the app free, our basis is our legitimate interest, balanced with your consent choices for tracking. You may also lodge a complaint with your local data-protection authority. To exercise any right, email support@sekana.app.

Your privacy rights (US states)

Depending on your US state (for example, California), you may have the right to know, access, and delete personal information, and to opt out of its “sale” or “sharing.” We do not sell personal information. The use of advertising identifiers for targeted ads may be considered “sharing” under some laws, and you can turn this off through the App Tracking Transparency prompt (iOS), the in-app consent form, or your device’s ad settings, and continue using the app. To make a request, email support@sekana.app.

Children’s privacy

Sekana is not directed to children under 13 (or under the minimum age required in your country), and we do not knowingly collect personal information from them. If you believe a child has provided us personal data, contact us and we will delete it.

Security

We rely on encrypted connections, Firebase security rules that limit access to your own backup, and consent-gated collection. No method of transmission or storage is completely secure, but we take reasonable measures to protect your information.

Changes to this policy

We may update this policy as Sekana evolves. When we do, we will revise the “Last updated” date above and, for material changes, surface a notice in the app.

Contact us

Questions about your privacy? Email us at support@sekana.app.