Effective date: 7 October 2026
This policy explains how NhakaBox handles personal data in Tsumo by NhakaBox (the app for iPhone and Android) and when you buy Tsumo Premium on our website, nhakabox.com. The rest of our website and our shop are covered by our general Privacy Policy.
Who we are
Tsumo is made by NhakaBox, based in the Netherlands. NhakaBox is the controller of your personal data under the EU General Data Protection Regulation (GDPR).
- Email: tsumo@nhakabox.com
The short version
- You need a Tsumo account to use the app. You sign in with Apple on iPhone or with Google on Android.
- We store your account, your favourites, your game score and leaderboard name, and your Premium purchase, so they work across your devices.
- Tsumo has no adverts. We don't sell your data, and we don't send marketing emails.
- We use Google Firebase for app analytics, push notifications and app settings, and (on Android) crash reports. In the EU, UK and Switzerland, analytics only runs if you agree.
- You can delete your account at any time in the app, under Settings → Account → Delete account.
What we collect and where it comes from
Your account (from Apple or Google, when you sign in)
- An internal account ID that we create.
- The user ID that Apple or Google gives us for you, and which of the two you used.
- Your email address. With Apple you can choose "Hide My Email", in which case we get an Apple relay address instead of your real one.
- Your name, if Apple or Google shares it with us.
- On iPhone, a token from Apple that we keep encrypted. We only use it to cancel the Apple sign-in link when you delete your account.
- When you created the account and when you last signed in, and secure sign-in tokens for each device (we store only a scrambled version of them).
What you do in the app
- Favourites: the tsumo you save.
- Game: your best score and the name you choose for the leaderboard.
- Onboarding answers: who the app is for (student, teacher, parent or other) and, if you answer it, why you are using it.
Premium purchases
- Whether your account has Premium, and the purchase details we need to check it: platform, product, transaction ID, purchase date and whether it was refunded.
- This includes whether you had one of the old Tsumo subscriptions, so you can keep Premium.
- We never see or store your card or bank details.
Suggestions ("Suggest a Tsumo")
If you send us a suggestion, we receive the email address you type in (required), your phone number (optional), your suggestion, the search that led you there, and basic device information (device model, operating system and app version). This goes to our team as an email.
Device and security data
- To check that requests come from the genuine Tsumo app, the app uses Apple App Attest or Google Play Integrity. We store a key or result for your installation, not your identity.
- Our server processes your IP address to deliver the app's content and to limit abuse (rate limiting). Our server logs record requests, such as the address requested, the app version and the device type.
Push notifications
If you allow notifications, we receive a push token for your device, your platform, app version and time zone, and which notification topics you follow (for example "daily", or "premium" / "free"). This record is not linked to your account.
Analytics and crash reports (Google Firebase)
- Firebase Analytics records how the app is used: screens viewed, tsumo opened, favourited or shared, searches (the number of results, not what you typed), game results, purchases and sign-ins. It also records an app-instance ID, your device type and an approximate location based on your IP address. Once you sign in, these events are linked to your internal account ID (never to your email or name). We never send what you type (searches, suggestions, emails, phone numbers or names) to analytics.
- Firebase Crashlytics (Android only) collects crash reports and device diagnostics. They are not linked to your account.
Buying Premium on our website
When you buy on nhakabox.com, the checkout is run by RevenueCat (RevenueCat Web Billing), and payments are processed by Stripe. They collect your email address, payment details, billing country (and, where needed for tax, your address) and the purchase details. RevenueCat links the purchase to your Tsumo account when you open the redemption link in the app. We see the purchase, the email address and the country, but not your full card details.
Emails you send us
If you email us, we keep your message and email address to answer you.
What we don't do
- No adverts, and no advertising SDKs in the app.
- No selling or renting of your personal data.
- No marketing emails. We only email you to answer you, or about your purchase or account.
- No tracking across other companies' apps or websites.
Why we use your data, and our legal basis
| What we do | Legal basis (GDPR article 6) |
|---|---|
| Create and run your account, sync favourites and game data, show the leaderboard, give you Premium, let you restore purchases | Performance of our contract with you (6(1)(b)) |
| Sell Premium on our website and deliver it to your account | Performance of a contract (6(1)(b)) |
| Keep payment and invoice records for tax purposes | Legal obligation (6(1)(c)) |
| Check that the app is genuine, prevent abuse, keep server logs, fix problems with crash reports (Android) | Our legitimate interest in a secure and working app (6(1)(f)) |
| Analytics in the EU, UK and Switzerland | Your consent (6(1)(a)), which you can withdraw at any time |
| Analytics outside the EU, UK and Switzerland | Our legitimate interest in understanding how the app is used and improving it (6(1)(f)) |
| Onboarding answers | Our legitimate interest in understanding who uses Tsumo, so we can improve it (6(1)(f)) |
| Push notifications | Your consent, given when you allow notifications (6(1)(a)) |
| Read and answer suggestions and emails | Our legitimate interest in improving the collection and answering you (6(1)(f)) |
| Respond to legal requests, protect our rights | Legal obligation or legitimate interest (6(1)(c) or (f)) |
Who receives your data
We use these service providers. Those marked "processor" only handle data for us, under our instructions and a data processing agreement.
| Provider | What they do for Tsumo | Role |
|---|---|---|
| Apple | Sign in with Apple, App Attest, App Store purchases, delivering push notifications (APNs) | Apple's own services, under Apple's privacy policy |
| Sign in with Google, Play Integrity, Google Play purchases | Google's own services, under Google's privacy policy | |
| Google (Firebase) | Analytics, Crashlytics (Android), Cloud Messaging (push), Remote Config (app settings); the consent form (Google User Messaging Platform) | Processor |
| RevenueCat, Inc. | Manages Premium purchases from the App Store, Google Play and our website; runs the website checkout and sends the receipt and redemption email | Processor |
| Stripe | Processes card payments for website purchases | Payment provider; Stripe also processes some data as an independent controller, for example to prevent fraud and meet its legal duties |
| MongoDB, Inc. (MongoDB Atlas) | Hosts our database | Processor |
| Cloudflare, Inc. | Connects the app securely to our server | Processor |
| Vercel Inc. | Hosts a standby copy of our server | Processor |
| Our hosting provider | Runs our production server | Processor |
| Resend | Sends suggestions from the app to our team's mailbox | Processor |
| Our email provider | Hosts our email (tsumo@nhakabox.com) | Processor |
Your leaderboard name and score are visible to other Tsumo users. We may also share data when the law requires it, for example with tax authorities or in response to a valid order from a court or authority.
Transfers outside the European Economic Area
Some of these providers are based in, or use systems in, the United States or other countries outside the EEA. When your data goes outside the EEA, we rely on safeguards that the GDPR allows: an adequacy decision (such as the EU-US Data Privacy Framework, where the provider takes part in it) or the European Commission's Standard Contractual Clauses. You can ask us for more information about these safeguards.
How long we keep your data
| Data | How long |
|---|---|
| Account, favourites, game data, onboarding answers, Premium record on your account, your leaderboard entries | Until you delete your account. Deletion is immediate and nothing about the account is kept on our server. |
| Sign-in token for a device | Stops working after 180 days without use, or when you sign out; removed when you delete your account |
| Push notification record | Removed when you turn off notifications in the app. Otherwise kept until it is no longer needed to send you notifications; we review these records regularly |
| Suggestions and emails you send us | Until they are no longer needed to answer you or to handle your suggestion; we review them regularly |
| Server logs | 14 days |
| Rate-limiting records (with IP address) | A few minutes |
| Firebase Analytics | Until it is no longer needed to understand how Tsumo is used. Google deletes it automatically at the end of the retention period set in our Google Analytics settings, and we review that setting regularly |
| Crashlytics crash reports (Android) | Kept by Google for up to 90 days |
| Payment and invoice records for website purchases | 7 years, as required by Dutch tax law |
Apple, Google, RevenueCat and Stripe keep their own records of purchases you made through them. Deleting your Tsumo account does not delete those. RevenueCat keeps the purchase history it holds under your (deleted) account ID. If you want it removed, email us.
Deleting your account
- In the app: Settings → Account → Delete account, then confirm. Your account and everything stored with it on our server is deleted straight away, including your leaderboard entries. On iPhone we also cancel the Sign in with Apple link.
- Without the app: follow the steps at tsumo.katanda.xyz/account/delete, or email tsumo@nhakabox.com from the email address on your Apple or Google account, with the subject "Delete my Tsumo account". We delete it within 30 days and reply when it's done.
Purchases made through the App Store or Google Play belong to your Apple ID or Google account. If you sign up again with the same one, "Restore purchases" brings Premium back. A Premium purchase made on our website belongs to the account you redeemed it on. If you delete that account, email us before you sign up again so we can help.
Your choices
- Notifications: turn the daily Tsumo notification on or off in Tsumo's Settings, or turn off all notifications for Tsumo in your phone's settings.
- Analytics (EU, UK and Switzerland): you choose in the consent form when you first open the app. You can change your choice at any time in Settings → Privacy options.
- Leaderboard: you choose the name shown on the leaderboard. It doesn't have to be your real name.
- Suggestions are optional, and the phone number is optional.
- Sign out at any time in Settings → Account.
Your rights
Under the GDPR you have the right to:
- access the personal data we hold about you and get a copy;
- have incorrect data corrected;
- have your data deleted;
- restrict how we use your data;
- object to our use of your data based on legitimate interests;
- receive the data you gave us in a common, machine-readable format (data portability);
- withdraw your consent at any time, without affecting what we did before.
To use these rights, email tsumo@nhakabox.com. We may ask you to confirm it is your account. We answer within one month.
You can also complain to the Dutch data protection authority, the Autoriteit Persoonsgegevens, or to the authority in the EU country where you live or work. We would appreciate the chance to help you first.
Children
Tsumo is made for a general audience, including students and families. Tsumo is an educational app. If you are below the age at which you can consent to the processing of your personal data in your country, ask a parent or guardian before you create an account or agree to analytics. If you are a parent or guardian and think your child gave us personal data without your permission, email us and we will delete it.
Security
We use encrypted connections (HTTPS) between the app and our server, check that requests come from the genuine app, store sign-in tokens only in scrambled (hashed) form, encrypt the Apple sign-in token, and limit who can access our systems. No system is completely secure, but we work to protect your data.
Changes to this policy
We may update this policy when Tsumo changes. We will post the new version on this page and change the effective date. If a change is important, we will also tell you in the app.
Contact
Questions about this policy or your data: tsumo@nhakabox.com
NhakaBox, the Netherlands