Privacy Policy

Effective 10 October 2026. Last updated 10 October 2026.

This Privacy Policy explains how RHH LLC ("RHH LLC", "we", "us" or "our") collects, uses, shares and protects information when you use the StackDays app on iPhone and Android, the StackDays website and related services (together, the "Service"). It should be read together with our Terms of Use.

1. Who we are

StackDays is operated by RHH LLC, which decides how and why your personal information is processed (the "controller" under the GDPR and similar laws). On Google Play the app is published through a developer account held on behalf of RHH LLC; this policy applies the same way there. Contact for anything in this policy: cristidumi96@gmail.com.

2. Information we collect

2.1 Account information

• your email address;
• the display name and avatar colour you choose;
• a unique user id created by our authentication service, and your invite code;
• the sign-in method you used: Apple, Google, Facebook, or email and password;
• the date your account was created.

Passwords for email accounts are handled by Google Firebase Authentication and are never visible to us. When you use Apple, Google or Facebook, we never receive your password. With Sign in with Apple you can hide your email, in which case we receive a private relay address from Apple.

2.2 Your habits and progress

The habits you create (name, emoji, colour, unit, goal, schedule and reminder time), the entries you log (dates and quantities), streak powers you use, your Home layout, and the badges and milestones worked out from them.

2.3 Friends, challenges and team chat

Friend requests and connections, the challenges you create or join, your progress within them, the messages you send in a challenge's team chat, and any reports or blocks you make. If you report a message, we store a copy of it with its author and your report so we can review it.

2.4 Activity data from Apple Health and Health Connect

Only if you link a habit to it, StackDays reads the specific metric you authorise (steps, running, swimming or cycling distance, or workout minutes) for the current day, to fill in that habit's progress. It stores the resulting habit entry, never a separate copy of your health records, and never writes anything back to Apple Health or Health Connect. Health data is never used for advertising or shared with third parties for their own purposes.

2.5 Purchases

Subscriptions are bought through the Apple App Store or Google Play. Our subscription service, RevenueCat, receives your user id, the product you bought, transaction ids, purchase, renewal and expiry dates, store receipts, your store country and currency, and basic device information. We use this only to unlock access, restore purchases and prevent fraud. We never receive your card or bank details.

2.6 Analytics and crash reports

StackDays uses Google Firebase Analytics and Firebase Crashlytics. They record app events (for example that a habit was logged or a screen opened), device and operating system information, app version and crash diagnostics, linked to your StackDays user id. On Android, Firebase Analytics may also read your device's advertising ID unless you have reset or turned it off in Android settings. We use this information only to understand how StackDays is used and to fix problems, not to advertise to you, and we do not sell it.

2.7 Facebook Login

If you choose to sign in with Facebook, Meta's Facebook SDK processes that sign-in and receives information about your device and the login. On iPhone, StackDays shows Apple's tracking permission prompt before Facebook Login, and you can decline it.

2.8 Technical information

When the app connects to our service providers (Google Firebase, RevenueCat, Apple, Google, and Meta when you use Facebook Login), they receive the technical information every internet connection carries: your IP address, device type, operating system and app version, and the time of the request. They use it to deliver their service, keep it secure and prevent abuse.

2.9 When you contact us

If you email us, we receive your email address and whatever you include in your message.

2.10 What we do not collect

Your precise location, contacts, photos, microphone recordings, browsing history, or health information beyond the activity metrics you link to a habit.

3. What stays on your phone

• Reminders and notifications are scheduled on your phone. We do not use a push notification service and do not collect notification tokens.
• Appearance settings (theme, accent colour, text size, haptics), vacation mode dates and similar preferences.

4. How we use information, and our legal bases

• Running the app: your habits, streaks, statistics and reminders, kept in sync across your devices (performance of our contract with you).
• Friends, challenges and team chat, including showing your name, streak and challenge progress to the people you connect with (performance of our contract with you).
• Subscriptions, free trials and restoring purchases (performance of our contract with you).
• Analytics and crash reports to improve StackDays and fix problems (our legitimate interest in a working, improving app).
• Security, moderation of reported messages, and fraud and abuse prevention (our legitimate interest in keeping the Service safe, and app store rules).
• Answering your emails and requests (performance of our contract, or our legitimate interest in helping you).
• Tax and accounting records, responding to lawful requests, defending legal claims (legal obligation, or our legitimate interest in protecting our rights).
• Activity data from Apple Health or Health Connect, and notifications (your consent, given through your phone's permission prompts; you can withdraw it at any time in your phone's settings).

We do not use your information for advertising, and we do not make decisions about you by automated means that have legal or similarly significant effects.

5. Who can see your information

Only you can see your full habit list and entry history in the app. Friends you connect with can see your display name, avatar colour and streak; to work out your streak, the app on their phone reads your habits and entries, but it shows them only the streak. Challenge members can see your progress within that challenge and the messages you send in its team chat. Blocking someone is stored on your own profile and is not revealed to them.

6. Who we share information with

We share personal information only with the service providers that run StackDays for us, and only as far as each one needs:

• Google (Firebase Authentication, Cloud Firestore, Firebase Analytics, Firebase Crashlytics, Firebase Hosting, Google Sign-In, Google Play): accounts, storing your data, analytics, crash reports, this website, Google sign-in and Android purchases.
• Apple: Sign in with Apple and App Store purchases.
• Meta Platforms: Facebook Login, only if you choose it.
• RevenueCat, Inc. (United States): managing subscriptions and purchase records.

Apple Health and Health Connect run on your phone; StackDays reads from them only with your permission. We may also disclose information when the law requires it (for example a valid court order), to protect the safety, rights or property of our users, the public or RHH LLC, to investigate fraud or abuse, or as part of a merger, acquisition or sale of all or part of our business, in which case this policy will continue to apply to your information and we will tell you about the change.

We do not sell your personal information, and we do not share it for cross-context behavioral advertising, as those terms are used in California and other US state privacy laws.

7. International transfers

RHH LLC is a United States company, and our providers process information in the United States and other countries. Where the law of your country requires safeguards for such transfers, we rely on recognised mechanisms such as the EU-U.S. Data Privacy Framework (and its UK and Swiss extensions) where the provider is certified, or the European Commission's Standard Contractual Clauses.

8. How long we keep information

• Account, habits, entries, friends and challenge participation: until you delete your account. Deletion removes them from our live databases straight away.
• Team chat messages: until you delete your account, except a copy kept as part of an open moderation report.
• Analytics and crash diagnostics: on Firebase's own retention schedule, after which they are deleted automatically.
• Purchase and transaction records (RevenueCat, Apple, Google): as long as tax, accounting and anti-fraud rules require.
• Emails with us: as long as needed to deal with your request and any follow-up.
• Provider logs and backups: for a limited period under each provider's own schedule.

9. Deleting your account

You can delete your account at any time:

• in the app: Settings, Delete account;
• on the web: stackdays-efb6b.web.app/delete-account.html;
• or by emailing cristidumi96@gmail.com from the address on your account. We complete email requests within 30 days.

Deleting your account permanently deletes your profile, every habit and entry you have logged, your friend connections and your challenge membership, and removes your sign-in from Firebase Authentication. In-app deletion takes effect immediately and cannot be undone. Copies of reported messages are kept until the report is closed. Purchase records that tax and accounting rules require us or the stores to keep are not deleted.

Deleting your account does not cancel a subscription. Cancel it in your App Store or Google Play settings first.

10. Your privacy rights

Depending on where you live, you may have the right to:

• access the personal information we hold about you and get a copy of it, including in a portable, machine-readable format;
• correct inaccurate information (most of it you can change directly in the app);
• delete your information;
• restrict or object to certain processing, including processing based on our legitimate interests;
• withdraw consent at any time, without affecting processing that happened before;
• opt out of the sale or sharing of personal information or targeted advertising (we do none of these);
• not be treated differently for using any of these rights;
• complain to a data protection or consumer authority, such as the supervisory authority where you live in the EEA or the Information Commissioner's Office in the UK.

To use any of these rights, email cristidumi96@gmail.com. To protect your account, we may ask you to write from the email address on the account or confirm your identity in another way. We reply within one month (GDPR) or 45 days (US state laws), and tell you if we need longer as the law permits.

11. Children

StackDays is not directed at children. We do not knowingly collect personal information from children under 13, or under the age set by the law of your country if higher. If you believe a child has given us personal information, email us and we will delete it.

12. Security

We protect your information with encrypted connections, encryption at rest by our providers, and database rules that limit who can read and change each piece of data. No one at RHH LLC looks at your data except when you ask us to help with your account, when reviewing a report you or someone else made, or when the law requires it. No system is perfectly secure, and we cannot guarantee that information will never be lost, corrupted, accessed or disclosed without authorisation. If a breach affects your information, we will notify you and the authorities as the law requires.

13. Your choices

• Turn notifications and Apple Health or Health Connect access on or off in the app or in your phone's settings.
• Choose what you share by choosing who you add as a friend and which challenges you join.
• Delete your account and data at any time (section 9).

14. Notice for California and other US state residents

In the last 12 months we collected these categories of personal information: identifiers (email address, user id), commercial information (subscription and purchase records), internet or network activity (the analytics, crash and technical data in sections 2.6 and 2.8), and other information you provide (habits, entries, friends, challenges and chat messages). We collect them from you, your device and the sign-in and store providers you use, for the purposes in section 4, and disclose them only to the service providers in section 6 and to the friends and challenge members you share with. We do not sell or share personal information for cross-context behavioral advertising.

15. Changes to this policy

We will update this policy when StackDays or the law changes. The date at the top shows the latest version. If a change is significant, we will tell you in the app or by email before it takes effect and, where the law requires, ask for your consent.

16. Contact

RHH LLC, operator of StackDays. Email: cristidumi96@gmail.com. Website: stackdays-efb6b.web.app.