Privacy Policy
- You don't need an account, login, or profile to use duet — we don't ask who you are.
- We use no third-party advertising SDKs and no third-party analytics SDKs, and we do not track you across other apps or websites.
- We never sell your personal information or share it with data brokers.
- Anything you provide to the app (such as photos or text inputs) is used only to produce the result you asked for — nothing else.
- You stay in control: device permissions are optional and can be changed at any time in iOS Settings.
1. Who we are
duet is a mobile application for iOS published by EXO Studio, based in Hanoi, Vietnam ("EXO Studio", "we", "us", or "our"). This Privacy Policy explains what information the app does and does not handle, how any information is processed, and the choices and rights available to you.
We designed duet to be privacy-friendly by default. The app does not require you to create an account, log in, or provide identifying information in order to work. If you have questions about anything in this policy, please reach out using the details in the Contact us section.
2. Information we collect
We aim to collect as little as possible. In practice, that means:
Information we do not collect
- No account details — the app has no sign-up, login, or user profile.
- No names, email addresses, phone numbers, or contact lists.
- No advertising identifiers gathered through third-party ad networks.
- No cross-app or cross-site tracking, and no data collected for third-party advertising or analytics SDKs.
- No sale of personal information to anyone, for any purpose.
Information you provide to the app
To do what you ask, the app may work with content you choose to give it — for example, a photo you select or text you type. This content is processed only to generate the result you requested and is not used for any other purpose, profiling, or advertising. Where the feature allows, this processing happens on your device, and content is not retained after the result is produced.
Basic technical information
Like most apps, standard technical information (such as app version, device model, or operating system version) may be handled locally to help the app run correctly and to diagnose crashes. We do not use this information to identify you personally.
3. How data is processed
The app is built to keep processing close to you. Where a feature can run entirely on your device, it does — content you provide is handled locally and is not sent to us or to any third party. When a feature genuinely requires a supporting service to function (for example, to complete a request the device cannot perform alone), only the data strictly needed for that request is transmitted, it is used solely to return your result, and it is not stored longer than necessary to complete the task.
We do not build advertising profiles, we do not enrich data with outside sources, and we do not combine your inputs across sessions to identify you.
4. How we use information
When we do handle information, we use it only for the limited purposes below.
| Data | Purpose | Legal basis (GDPR) |
|---|---|---|
| Content you provide (e.g. photos, text inputs) | To generate and return the result you requested | Performance of a contract / your consent |
| Device permission responses (e.g. camera, photos) | To enable the specific feature you chose to use | Your consent |
| Basic technical & crash information | To keep the app stable, fix bugs, and maintain security | Legitimate interests (reliable, secure service) |
| Support messages you send us | To respond to your question or request | Legitimate interests / your consent |
We do not use your information for advertising, for selling to third parties, or for automated decisions that produce legal or similarly significant effects about you.
5. Service providers
We keep third-party involvement to a minimum. Where the app relies on standard platform infrastructure — for example, Apple's operating-system services for app delivery and crash reporting, or a hosting or processing provider strictly needed to complete a feature — those providers act on our behalf and only for the purpose we specify. Any such provider is expected to protect the data appropriately and is not permitted to use it for their own advertising or profiling.
We do not integrate third-party advertising networks or third-party analytics SDKs into duet. We do not name specific vendors here because our providers may change over time; whenever a provider is involved, the principles in this policy continue to apply.
6. Data sharing
We do not sell, rent, or trade your personal information, and we do not share it for cross-context behavioral advertising. We may disclose information only in these limited situations:
- With service providers acting on our behalf, strictly to operate a feature you use, as described above.
- For legal reasons, if required by applicable law, regulation, legal process, or an enforceable governmental request.
- To protect rights and safety, where necessary to detect, prevent, or address security, fraud, or technical issues.
- In a business transfer, such as a merger or acquisition, in which case any recipient remains bound by this policy or a policy at least as protective.
7. Data retention
Because duet is built to process content and discard it, we retain as little as possible for as short a time as possible. Content you provide to a feature is kept only for as long as needed to produce your result and is not stored afterward where the feature runs on-device. Basic technical or crash information used to keep the app healthy is retained only for as long as it is useful for that purpose, and support correspondence is kept only for as long as needed to handle your request. When information is no longer needed, it is deleted or anonymized.
8. Data security
We use reasonable technical and organizational measures to protect information, including favoring on-device processing, encrypting data in transit where it is transmitted, and limiting access to any information we handle. No method of transmission or storage is completely secure, so while we work hard to protect your information, we cannot guarantee absolute security. If we ever become aware of a security incident that affects you, we will act promptly and comply with applicable notification obligations.
9. Device permissions
Some features may ask for an iOS permission so the app can do what you requested. Permissions are optional, are requested only when a feature needs them, and can be granted or revoked at any time in your device's Settings. The table below explains why each common permission may be requested.
| Permission | Why the app may request it | Required? |
|---|---|---|
| Camera | To capture a photo when you choose a feature that uses the camera | Only for camera-based features |
| Photo Library | To let you select an image to process; access can be limited to the photos you pick | Only when you import a photo |
| Notifications | To send you optional in-app reminders or status updates, if you enable them | Optional |
| Local storage | To save results you create back to your device, at your request | Only when you save output |
Declining a permission simply means the related feature will be unavailable; the rest of the app continues to work.
10. Children's privacy
duet is not directed to children under the age of 13 (or the minimum age required in your jurisdiction), and we do not knowingly collect personal information from children. Because the app requires no account and collects no identifying information, it is not designed to gather such data in the first place. If you believe a child has provided us with personal information and you would like it addressed, please contact us and we will take appropriate action.
11. Your rights (GDPR & CCPA)
Depending on where you live, you may have rights over your personal information. Because duet operates without accounts and generally does not retain your content, we often hold little or no personal information about you — but the following rights apply where relevant.
If you are in the European Economic Area or the UK (GDPR)
- The right to access, correct, or delete your personal data.
- The right to restrict or object to certain processing.
- The right to data portability.
- The right to withdraw consent at any time, without affecting prior processing.
- The right to lodge a complaint with your local data protection authority.
If you are a California resident (CCPA/CPRA)
- The right to know what personal information is collected and how it is used.
- The right to delete personal information we hold about you.
- The right to correct inaccurate personal information.
- The right to opt out of the "sale" or "sharing" of personal information — noting that we do not sell or share your personal information.
- The right not to be discriminated against for exercising your privacy rights.
To exercise any of these rights, contact us using the details below. We will respond within the timeframe required by applicable law and may need to verify your request before acting on it.
12. International transfers
EXO Studio is based in Vietnam, and the app may be used worldwide. Where a feature requires a supporting service, the limited data involved may be processed in countries other than your own, which may have different data protection laws. When such transfers occur, we take steps to ensure an appropriate level of protection consistent with this policy and applicable law, including using recognized safeguards where required.
13. Changes to this policy
We may update this Privacy Policy from time to time to reflect changes in the app, our practices, or legal requirements. When we make a material change, we will update the "Last updated" date at the top of this page and, where appropriate, provide a more prominent notice within the app. We encourage you to review this policy periodically. Continued use of duet after an update means you accept the revised policy.
14. Contact us
If you have questions, requests, or concerns about this Privacy Policy or your information, please contact us:
- EXO Studio — Hanoi, Vietnam
- Email: exostudio.feedback@gmail.com
We will do our best to respond promptly and to help with any privacy-related request.