Privacy Policy
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Kioku is an educational flashcard app for learning Japanese, developed by Kioku Corp. This policy explains what we collect, why, and what you can do about it. The short version: your study data lives on your device and, when you sign in, is synced to your account. We do not show ads, we do not use third-party trackers and we never sell your data.
Who is responsible
Kioku Corp ("we") is the controller of the personal data described here. You can reach us at support@appkioku.com.
What we collect
Data you give us: the name you type in the app, the e-mail used to sign in with a code and, if you sign in with Apple or Google, the identifier, name and e-mail provided by that service. With "Hide my e-mail" from Apple we receive only the relay address. Sign-in data is used to authenticate your account and associate it with your Kioku profile and progress.
Study data: your cards, progress, streak, daily goal, study preferences, character, XP, points, rubies, energy, items, achievements, activity history, custom decks and favorites. This is stored on your device and, when you sign in, synced to your account using Supabase so you can continue on another device. Offline changes wait for a connection before they can be synced. You can also export a backup yourself.
Purchases: paid purchases and subscriptions are not available in this test version. The app does not collect your card or bank details.
Reports you send: the reason, your optional comment, the card or sentence involved, the app language and platform.
Technical data: the app may record crash information (app version, device model, OS version) to fix bugs. We do not run analytics today; if we add product analytics in the future, this policy will be updated first and, where the law requires, you will be asked for consent.
What we do not do
No advertising, no advertising identifiers, no third-party trackers, no selling or renting of personal data, no profiling for marketing.
Why we use it (legal bases)
To run the app and your account (performance of a contract — LGPD art. 7, V; GDPR art. 6(1)(b)). To fix bugs, prevent abuse and improve the lessons (legitimate interest — LGPD art. 7, IX; GDPR art. 6(1)(f)). For anything optional, such as future analytics, your consent (LGPD art. 7, I; GDPR art. 6(1)(a)), which you can withdraw at any time.
Where it is stored and for how long
On your device, until you erase the progress or uninstall the app. In your account (Supabase, encrypted in transit and at rest), while the account exists. When you delete your account, the data is removed within 30 days; copies in backups are purged within 90 days. Purchase records are kept for as long as tax and consumer law require.
Who we share it with
Only processors needed to run the service: Apple and Google (sign-in), Supabase (authentication, hosting and database), and Resend (delivery of e-mail sign-in codes and receipt of support messages). They act on our instructions. We may also disclose data when the law requires it or to protect the rights and safety of users.
Your rights (LGPD and GDPR)
You can confirm whether we process your data, access it, correct it, ask for deletion, obtain a copy (portability — use Settings › Backup › Export at any time), withdraw consent and object to processing based on legitimate interest.
To delete everything, use Settings › Account › Delete account, or write to us. We answer requests within 15 days (LGPD) or one month (GDPR). You may also complain to the Brazilian data protection authority (ANPD) or to your local EU/EEA authority.
Children
Kioku is for people aged 13 and over. We do not knowingly collect data from younger children; if you believe a child under 13 is using Kioku with an account, contact us and we will delete the data.
Security
Data is transmitted over HTTPS and stored with access limited to what the service needs. No system is perfectly secure; keep your Apple/Google account protected and use a backup if your device is shared.
International transfers
Our processors may store data outside Brazil or the EU (for example in the United States) under standard contractual clauses or equivalent safeguards.
Changes
When this policy changes in a meaningful way, the app will show the new version and ask you to accept it again before you continue.