Who is responsible for your data
The data controller is Sparkling Minds OÜ, Mõisa tn 4, 13522 Tallinn, Estonia. You can reach us at privacy@duoheart.app, and that is also the address for any request about the data we hold.
If you are in the EU or the UK you have the right to ask what we hold about you, to have it corrected or erased, to object to how we use it, and to complain to your data protection authority. In Estonia that is the Data Protection Inspectorate (Andmekaitse Inspektsioon). Deleting your account from Profile erases your account and its data outright.
The short version
Duoheart is built so that we, the people who run it, cannot read your messages, your daily answers, or your call audio and video. They are encrypted on your device before they ever leave it, using a key only you and your partner hold. We store ciphertext, not your conversation.
There is one deliberate exception, and we would rather you read it here than discover it: the optional AI features cannot work on text nobody can read, so what you write to them is not end-to-end encrypted. The app says so on those screens, and the section below says exactly what happens to it.
What we collect
We collect the minimum needed to run the service:
- Your email address, used to sign you in with a one-time code, and to tell you about your own invite: if you invite a partner and nobody has joined after a day, we remind you and send the link again, at most twice. Every such message carries a one-click unsubscribe that needs no login. We send nothing else - no newsletter, no marketing - and we never pass your address to anyone.
- Your public encryption key, so your partner’s device can securely share your couple’s conversation key with you.
- Encrypted message and answer content - we store the ciphertext only, we do not hold the key to decrypt it.
- Basic account and subscription metadata (creation date, language, subscription status) needed to operate the app.
- Ordinary website statistics: which page was opened, which site or search engine you arrived from, your country and city, and whether the browser is a phone or a desktop. We do not store your IP address. To count visitors without following anyone, the address and browser are hashed together with a secret and the date, which produces a number that is different tomorrow and cannot be turned back into you. No third-party analytics, no advertising network, no profile.
What we never see
The content of your messages, your daily question answers, your photos and videos sent in chat, and your call audio or video. All of this is end-to-end encrypted with a key derived on your devices - Duoheart’s servers never possess it. This is the whole of the app except the AI features described next, and it is where your relationship actually lives.
The AI features, and what they do see
Three parts of the app use an AI model. A model cannot read ciphertext, so anything you deliberately write to one of them is processed in readable form. None of them can see your encrypted chat, your answers, your photos in chat or your calls.
- The AI couples therapist is a separate thread you choose to open. What both of you write there, and the replies, are stored in readable form in our database and sent to OpenAI to generate each reply. We can technically read that thread, and the app tells you so on the screen before you write in it. You can wipe it at any time from that screen, and deleting your account deletes it. Your encrypted chat is not part of it and is never sent anywhere.
- Duo, the demo partner, stands in before your real partner joins. What you write to Duo, and any photo you send Duo, go to Google (Gemini) to produce the reply. Demo content is not part of your couple’s encrypted store: it stays on your device and the app wipes it when your real partner joins.
- Tappable answer suggestions send only the daily question itself, which is the same for every couple and already public, to OpenAI. Your own answer is never sent.
You can use Duoheart fully without any of these. If you never open the therapist thread and never chat with Duo, no text of yours is ever processed in readable form by us or by a model provider.
Third-party services
We use Supabase for authentication, database, and realtime infrastructure, and standard payment processors for subscriptions. These providers process encrypted data or billing information - never your decrypted conversation.
The AI features above are the exception, and they are the only one: we use OpenAI (for the therapist thread and answer suggestions) and Google (for the demo partner Duo) as processors for exactly the text, and in Duo’s case the photo, you send to them. After you delete something here it is gone from our database, while a model provider may hold a short-lived copy under its own API retention terms.
Your rights
You can request a copy of your account data or request deletion of your account and all associated data at any time by contacting privacy@duoheart.app. Deleting your account permanently deletes your encrypted data - we cannot recover it afterward, by design.
Changes
If we make material changes to this policy, we’ll notify you in the app before they take effect.
Contact
Questions about this policy: privacy@duoheart.app