Privacy policy

Balik is developed by an independent developer (contact above), not a company. The App is built on Google Firebase, which acts as our data processor and host (Firestore database, Authentication / Identity Platform, Cloud Storage, Cloud Functions, App Check).

2.1 Account information

To use the App you sign in with Google Sign-In. We receive your Google account's email address and unique account ID from Google, which we use solely to create and identify your account. We never see or store your Google password. There is no anonymous or guest mode — an account is required.

2.2 Profile information you create

• A username you choose (or skip). Usernames are unique, so a reservation record links the lowercase form of your username to your account.
• An avatar, which is procedurally generated art rather than an uploaded photo. You pick a seed word, and the image is generated by the third-party service DiceBear(api.dicebear.com) from that seed. Your chosen seed and your device's IP address reach DiceBear when the image loads; no account data is sent.
• Optional display preferences (theme, accent color, app icon, UI language).

2.3 Learning activity and progress

• Course selections, lesson and exercise completions, placement- and skip-test results.
• XP (experience points) and level, per course.
• Daily streak data (current streak, longest streak, active days, streak-freeze usage).
• Word-bank flashcard review history and spaced-repetition scheduling data, including per-card review logs used to tune the scheduler.
• Reading progress for graded readers and webtoons.
• Progress in the in-app games (crossword, document inspection).
• Weekly quest progress and chest claims.
• Aquarium state: fish you own, their growth stage and position, decorations and tank theme.
• In-app inventory items (for example streak-freeze tokens and fish feed), and any redeemed gift codes (a redemption record only).

2.4 Social and public features

Some information is deliberately visible to other users:

• Leaderboards for a course show your username, avatar and XP total.
• A public profile mirror carries your username, avatar, per-course XP and streak, so friends and league members can see your standing.
• A public aquarium mirror lets other users visit your tank.
• Friends: friend requests and friendships, identified by username and account ID.
• Leagues: league membership, invitations, and standings.

You control how much of this exists by choosing whether to set a username and whether to use the friends and leagues features. Leaderboard and public-profile entries are created when you earn XP.

2.5 Content contributions (authors and moderators only)

If you are granted a content-author or moderator role, the course content you write or edit is stored along with your account ID, and a permanent revision history of those edits is kept so changes can be reviewed, merged and reverted. This applies only to accounts we have explicitly given a content role; ordinary learners never write course content.

2.6 Purchases and Pro subscriptions

Pro subscriptions are sold through Google Play Billing (Android). We never see or receive your payment card details, billing address, or Google Pay information — Google handles the entire transaction.

What we do store, to know whether your subscription is active: the Play purchase token for your subscription, the product and plan you bought, and its current status and expiry as reported to us by Google's Play Developer API. We verify every purchase server-side against that API before granting Pro, and Google notifies our server when a subscription renews, lapses, is cancelled or is refunded. Refunds and cancellations are managed by you in Google Play.

Gift codes, where used, record only the fact of redemption and which account redeemed which code.

2.7 Microphone (speaking exercises)

Some lessons contain speaking exercises. When you open one, the App asks your device for permission to use the microphone so you can record yourself saying a phrase, hear it back, and compare it with the example recording. You can decline; the lesson continues either way, and we do not ask again unless you re-enable it yourself from the exercise.

Your recording is never uploaded. It is written to a temporary file on your device, compared with the example recording entirely on your device, and deleted as soon as you retry, move on, or leave the lesson. We never receive it, never store it, and never use it to train anything. No transcript and no speech-recognition result is produced or sent anywhere — the comparison is signal processing over timing and intonation, not speech recognition.

2.8 Notifications and the home-screen widget

• Study reminders are scheduled and delivered entirely by your device. We do not operate a push-notification server and send you no remote messages. Reminder times and preferences are stored locally on your device. On Android 13+ and on iOS, the App asks for notification permission; declining only disables reminders.
• The optional Android home-screen widget displays your current streak and the number of flashcards due. Those two numbers are written to the widget's own on-device storage so the launcher can draw them; they leave your device no more than the same numbers already do inside the App.

2.9 Device, network and security data

• Firebase App Check attestation signals (Google Play Integrity on Android, DeviceCheck on iOS, reCAPTCHA on web) — used only to verify that requests come from a genuine, unmodified copy of the App, not to identify you personally.
• Sign-up rate limiting: when an account is created, our server counts recent sign-ups per network address using a one-way hash of the IP address. The raw IP is not written down, the counter carries no account ID, and the counters expire on a rolling hourly basis. This exists to stop bulk automated account creation.
• Abuse rate limits on actions such as friend requests, username changes and gift-code attempts are counted per account.
• Account restrictions: if an account repeatedly violates our terms, we record a timed restriction or a ban on that account, along with the reason.
• Standard technical data that any network request carries, most importantly your IP address, is handled at the infrastructure level by Google Cloud/Firebase under their own policies. We do not separately log or retain IP addresses ourselves, apart from the hashed sign-up counter described above.

2.10 Third-party content loaded inside the App

Some course material is delivered by third parties, and opening it means your device contacts them directly:

• YouTube: some lessons embed YouTube videos. Playing one is a request to YouTube/Google, which may set cookies or similar identifiers and collect usage data under Google's own privacy policy. We receive nothing from these embeds ourselves.
• Google Fonts: certain screens use fonts fetched from Google's font service, which receives your IP address as part of the request.
• DiceBear: avatar images, as described in §2.2.
• External links you tap (for example licence and attribution links) open in your browser and are governed by the destination site's own policy.

2.11 Data stored only on your device

Lesson audio, images, webtoon panels and other media you view are cached permanently on your device so they work offline and don't re-download. Various preferences (theme, playback settings, reminder times, fish positions, reading preferences) are also device-local. You can inspect and delete cached media at any time from Profile → Downloaded content, per course, and deleting the App removes all of it.

2.12 What we do NOT collect

• No advertising. The App shows no ads, contains no advertising SDK, and uses no advertising identifier (Android Advertising ID / IDFA). If that ever changes, this policy will be updated first.
• No third-party analytics or crash-reporting SDKs.
• No contacts, photos, location, or camera access.Microphone access is limited to §2.7, and no audio ever leaves your device.
• No payment card details.
• We do not sell your personal information, and we do not share it with advertisers or data brokers.

• To operate the App: sync your progress across devices, award XP, track streaks, schedule flashcard reviews, and run the games and aquarium.
• To provide the social features you opt into (friends, leagues, leaderboards, aquarium visits).
• To deliver and verify Pro entitlements you have purchased.
• To prevent cheating and abuse — sign-up throttling, rate limits, XP-integrity checks, and, for accounts that violate our terms, timed restrictions or bans.
• To respond to support requests you send us.

We do not use your data for automated decision-making beyond these anti-abuse measures, and we do not use it to train machine-learning models.

Where the GDPR or UK GDPR applies, we rely on: performance of a contract for account, progress and subscription data; legitimate interests for security, anti-abuse and service integrity; and consent for optional device permissions (microphone, notifications), which you can withdraw at any time in your device settings.

• Google Firebase / Google Cloud hosts all app data as our infrastructure provider, under Google's own data-processing terms.
• Google Play processes subscription purchases and tells our server their status.
• Other users see only what §2.4 describes: your username, avatar, XP/streak, and aquarium, on leaderboards and to friends and league members.
• Third-party content providers (§2.10) receive requests directly from your device when you open their content.
• We may disclose information if required by law, or where necessary to protect the safety, rights, or property of our users or the App.

You can delete your account at any time from Profile → Remove account and request data removal. This deletes, from our systems: your profile, all learning progress and word-bank data, your friendships and pending friend requests, your league memberships (and any leagues you lead), your leaderboard entries, your public profile mirror, your username reservation, your roles and entitlements, and finally the sign-in account itself. The action is immediate and cannot be undone, and it also ends any Pro membership, including remaining gift-code time, which is not refunded or restored if you sign up again. You can also email us to request deletion — see our data removal page.

Some records survive account deletion, and only for as long as we need them:

• Purchase and subscription records tied to a Play purchase token, kept for billing, tax and fraud-prevention purposes.
• Course content contributed under a content role, and its revision history, since it forms part of the course other learners are using.
• Backup copies held by Google Cloud, which expire automatically on their own schedule.
• Anonymous, account-free security counters such as the hashed sign-up counter.

If you believe something about you remains after deletion, email us and we will remove it.

Access to your data is enforced by Firebase Security Rules — your personal progress is readable only by your own account — and by Firebase App Check, which blocks unauthorized and scripted access to our backend. Purchases are verified server-side rather than trusted from the device. Traffic is encrypted in transit, and cleartext HTTP is disabled in the App. No method of transmission or storage is completely secure, but we take reasonable steps to protect your information.

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

Your information may be processed on servers outside your country of residence, as determined by Google Cloud/Firebase's infrastructure regions, and by the third parties named in §2.10.

Depending on where you live, you may have rights to access, correct, export, or delete your personal data, to object to or restrict certain processing, and to lodge a complaint with your local data-protection authority. You can exercise most of these directly in the App (profile editing, username changes, cached-content deletion, account deletion) or by contacting us at the email below. We do not discriminate against you for exercising these rights.

We may update this policy from time to time. We will update the "Last updated" date above when we do, and for material changes we will make reasonable efforts to notify users in-app.

Questions about this policy or your data: [email protected].