SprintDuo Privacy Policy

This policy explains how the SprintDuo app processes your personal data. Terms such as "App", "Account", "Couple" and "Partner" have the meaning given in our Terms of Service.

In short

You sign in with your phone number and an SMS code. We do not store your full number in plain text.
Your answers, game choices and messages are encrypted in our database – on the server, not end-to-end.
Your Partner sees your answer only after they have answered too.
We do not show ads, sell data, use third-party analytics or tracking tools, or profile you.
You can download your data and delete your Account in the App at any time.

1. Data controller

The controller of your personal data is 8CELLS Jarosław Kaczmarski, based in Poland, a sole trader registered in the Polish Central Register and Information on Economic Activity (CEIDG), tax ID (NIP) 7962621938, REGON 366811404 ("we", "us"). The postal address for written correspondence is listed in our CEIDG entry (search by tax ID at biznes.gov.pl). For anything related to your personal data, write to hi@sprintduo.app.

We have not appointed a data protection officer, as we are not required to (Article 37 GDPR). Contact us at the address above about anything related to your data.

2. What data we process

Account and sign-in

Phone number. We do not store your full number in plain text in our database. We process it briefly to send and check your SMS code. We store a keyed hash of the number (HMAC), used to find your Account, plus the last 4 digits and the country code.
SMS code. One-time codes are sent and checked by our provider Twilio (the Twilio Verify service).
Name or nickname (up to 40 characters), which your Partner sees.
Confirmation that you are 18 or over and accept the Terms of Service.
PIN (optional, 6 digits) – stored only as a salted hash. If you start a reset of a forgotten PIN, the reset happens after 7 days and your Partner is informed.
Session tokens – stored only as hashes.

Couple and invitations

When you invite someone to form a Couple, you enter their phone number. We store it as a hash (HMAC) so that only the person who signs in with that number sees the invitation.

If you receive an invitation, your phone number was given to us by the person who invited you. You see the invitation only after signing in with that number. Invitations expire after 72 hours. You can accept, decline or block the sender – in that case we record the block, and the sender is not told about it.

We also process who you form a Couple with. An Account can belong to only one active Couple at a time.

Your content

answers to the daily question,
choices and guesses in mini games,
messages under completed activities,
reactions to revealed answers (for example a heart),
saved games (bookmarks).

Answers, game choices and messages are encrypted in our database with AES-GCM. The keys are held on the server and managed by us. This is not end-to-end encryption – we are technically able to read this content.

Only the controller has access to the keys. We have no tool for browsing your content and nobody reads it routinely. We read it only when strictly necessary: at your explicit request (for example when you report a bug), when handling a report of illegal content, or where the law requires it – and only to the extent needed. We never use it for advertising, analytics or training artificial intelligence models.

Answers are free text. Only write what you want to share with your Partner.

The "Closeness & intimacy" topic

This topic is optional. Its questions appear only when you have both switched it on, and your Partner cannot see which of you switched it on. Answers in this topic may reveal information about your sex life, which is a special category of personal data under Article 9 GDPR.

We process these answers only on the basis of your explicit consent (Article 9(2)(a) GDPR). When you switch the topic on in the Us tab, the App shows the consent text, and the topic is switched on only after you choose "I agree". We record when you gave consent so that we can demonstrate it. Consent is voluntary – without it you can still use all other features of the App.

You can withdraw it at any time by switching the topic off. We then:

permanently delete your earlier answers to questions from this topic and your messages and reactions under them – for questions you have both answered, your Partner will see "Answer deleted";
questions from this topic that your Partner has not answered yet disappear from your Couple's history together with any answer of yours, and no new ones appear;
delete the record of when you consented.

Your Partner's answers and messages under these questions are their data – they remain until your Partner withdraws their own consent or deletes their Account. Deleted content disappears from backups within the period given in section 7. Withdrawing consent does not affect the lawfulness of processing carried out before the withdrawal.

Settings and notifications

App language – to show content in your language.
Time zone as an IANA name (for example Europe/Warsaw), sent by the App – to align your Couple's day in the App with your local time.
Notification preferences.
Push notification token and device language – if you allow notifications. Notifications tell you about your Partner's activity (for example an answer, a message or an invitation) and never contain the text of answers or messages.

Reminders (if you turn them on) are scheduled by your phone. Their settings are stored only on your device and never reach us.

Technical and security data

Technical logs about how the Service is running: time, address and type of a request, response code, errors, and connection information provided by Cloudflare (for example the country derived from the IP address). Logs never contain the text of answers or messages, phone numbers or SMS codes.
IP address of your device, processed when it connects to our server. To protect the Service against abuse, we limit how many SMS codes can be sent, and for that purpose we store hashes (HMAC) of the phone number and IP address.

The App stores on your device only what it needs to work, such as session data and reminder settings.

Contacting us

When you write to us, we process your email address, the content of your message and any data needed to deal with your request, such as your phone number when you ask us to delete your Account.

3. Purposes and legal bases

Providing the Service – creating and running your Account, sign-in, PIN, pairing, showing content, notifications and data export: Article 6(1)(b) GDPR (performance of a contract).
The "Closeness & intimacy" topic: Article 9(2)(a) and Article 6(1)(a) GDPR (explicit consent).
The invited person's phone number: Article 6(1)(f) GDPR – our legitimate interest in letting the inviting person connect with the person they choose.
Security and abuse prevention (SMS limits, technical logs, the waiting period and Partner notification when a PIN is reset): Article 6(1)(f) GDPR – our legitimate interest in protecting the Service and Accounts.
Handling your rights and complaints and meeting legal obligations: Article 6(1)(c) GDPR.
Correspondence and establishing, exercising or defending legal claims: Article 6(1)(f) GDPR.

Providing your phone number, name and the confirmations required at sign-up is necessary to create an Account. Any other data you provide voluntarily when you use specific features.

4. What your Partner sees

Your name and the last 4 digits of your phone number – also in invitations you send.
Your answer to the daily question – only after they have answered too.
Your choices in mini games – once you have both finished the game.
Your messages and reactions under completed activities.

Your Partner cannot see your full phone number or which of you switched on the "Closeness & intimacy" topic. After the Couple ends (the Couple is disconnected or an Account is deleted), your former Partner loses access to your shared content, including yours.

5. Who processes data for us

We use providers that process data on our behalf as processors, under data processing agreements:

Cloudflare, Inc. – the Service's infrastructure: servers (Cloudflare Workers) and database (D1). Processes all Service data.
Twilio Ireland Limited and Twilio Inc. – sending and checking SMS codes (Twilio Verify). Process your phone number.
Google Ireland Limited – push notifications (Firebase Cloud Messaging). Processes the notification token, device language and notification content, which never includes the text of answers or messages.

On iOS devices, Firebase Cloud Messaging passes the notification to the Apple Push Notification service (Apple Inc.), which delivers it to your device. On Android, notifications are delivered by Google Play services.

We may also disclose data to public authorities where the law requires it. You download the App from the App Store or Google Play – Apple and Google process data related to your store account under their own terms.

6. Transfers outside the EEA

Our database (Cloudflare D1) runs in the Western Europe region. Requests from the App are, however, handled by the Cloudflare data centre closest to your device, and Cloudflare, Twilio, Google (including Google LLC) and Apple (notification delivery on iOS) may process data outside the European Economic Area, including in the United States. Such transfers are based on the European Commission's adequacy decision for the EU-US Data Privacy Framework (for certified companies) or on the standard contractual clauses approved by the Commission. You can ask us for information about the safeguards used.

7. How long we keep data

Account and your content – for as long as you have an Account. When you delete your Account, we immediately delete the Account (including notification preferences and tokens), answers, game choices, messages, reactions, saved games and sessions from the live database.
Content from the "Closeness & intimacy" topic – until you withdraw consent (section 2) or delete your Account.
Backups (restoring the database to a chosen point in time) – up to 30 days; after that, deleted data is gone from backups too.
Session tokens – until you sign out, the session expires or you delete your Account.
Invitations – valid for 72 hours; we delete them 30 days after they were sent, whether they were accepted, declined or expired.
Record of a blocked sender – until your Account or the sender's Account is deleted.
Technical logs – up to 7 days.
SMS rate-limit data – 48 hours.
Correspondence and complaints – 3 years after the matter is closed, and longer only where needed to establish, exercise or defend legal claims.

8. How we protect data

We do not use passwords – sign-in is based on SMS codes and an optional PIN.
We store your phone number as an HMAC hash, the last 4 digits and the country code.
We store your PIN and session tokens only as hashes.
We encrypt answers, game choices and messages in the database (AES-GCM, server-side keys), and only the controller has access to the keys.
Notifications never contain the text of answers or messages.

9. Your rights

You have the right to:

access your data and get a copy – in the Us tab, choose "Download my data" to get a JSON file with your data (your Partner's data is not included);
rectification – change your name in the App under "Edit profile";
erasure – in the App: Us → Danger zone → Delete account; without the App, follow the instructions on the "Delete your account" page;
restriction of processing;
data portability – you can take the exported JSON file to another service;
object to processing based on our legitimate interest;
withdraw consent at any time – for the "Closeness & intimacy" topic, simply switch it off (section 2 explains what happens then);
lodge a complaint with the President of the Personal Data Protection Office (Prezes Urzędu Ochrony Danych Osobowych, ul. Stawki 2, 00-193 Warszawa, uodo.gov.pl) or with the supervisory authority in the EU country where you live or work.

To exercise your rights, write to hi@sprintduo.app. We may ask you to confirm with an SMS code that the Account's phone number is yours. We will reply without undue delay and within one month at the latest. In exceptional cases this period may be extended by two further months – we will tell you if that happens.

10. Ads, analytics and profiling

We do not show ads and we do not use your content for advertising. We do not sell data. We do not use third-party analytics tools or tracking SDKs. We do not profile you and we do not make decisions about you based solely on automated processing. Editorial content, such as questions and games, is written by the SprintDuo team.

11. Minors

SprintDuo is only for people aged 18 or over. We do not knowingly process data of minors. If we learn that an Account belongs to a minor, we will delete it.

12. Changes to this policy

We may update this policy, for example when the App's features or the law change. The date of the last update is shown with this policy. We will tell you about significant changes in the App.