Terms of Use

These Terms of Use (“Terms”) are an agreement between you and Stackr Labs Incorporated, trading as Conscious Engines Studio (“we”, “us”), 251 Little Falls Drive, Wilmington, Delaware 19808, USA. They cover your use of the Duet PDF Reader app (“Duet” or “the app”) and Duet Pro. By downloading or using Duet, you agree to these Terms. If you don’t agree, please don’t use the app.

To accept these Terms, you must be old enough to form a binding contract where you live. If you’re not, a parent or guardian must accept them on your behalf, including for any purchase.

We grant you a personal, non-exclusive, non-transferable, revocable licence to use Duet, and Duet Pro if you buy it, on Apple-branded devices that you own or control, as permitted by Apple’s Usage Rules in the App Store Terms of Service.

You may not:

• copy, modify or distribute the app;
• reverse engineer or decompile it, or try to extract its source code, except where the law allows;
• bypass, disable or tamper with how Duet Pro is unlocked;
• rent, lease, sell or sublicense the app; or
• remove any proprietary notices.

We, and our licensors, own all rights in the app, including its design, code and branding. These Terms don’t give you any of those rights, apart from the licence above.

You keep full ownership of everything you bring into or create in Duet. That includes PDFs, highlights, clips, notes, tables, photos, ink, voice notes and pinned answers. We don’t access it, claim rights to it or use it for any purpose.

You are responsible for having the right to import and use the documents and photos you add to Duet, including any copyright or confidentiality obligations that apply to them.

Duet stores your content on your device only. We don’t operate cloud storage for it, so we can’t recover data if you lose your device, delete the app or delete documents. Back up anything you care about, for example with iCloud or device backups.

To unlock and restore Duet Pro, Duet uses RevenueCat, which processes a pseudonymous purchase record and never receives your content. Our Privacy Policy, at duetreader.app/privacy, explains how Duet handles information.

Duet’s AI features run on Apple Intelligence. By default they use Apple’s Private Cloud Compute, which needs an internet connection. If you choose On-Device under Assistant Model in Settings, they use Apple Foundation Models on your device instead.

• AI answers are generated automatically and may be incomplete, outdated or wrong, even when they’re based on your document.
• AI answers are not professional advice. That includes legal, financial, medical, academic and other advice. Don’t rely on them for decisions without checking the source yourself.
• Whether AI features are available depends on your device, your iOS version, your region, your language and Apple’s services. Apple may change these factors, and they are outside our control.

Don’t use Duet:

• to break the law;
• to infringe anyone’s rights; or
• to try to disrupt, misuse or bypass the app, Duet Pro or the Apple services it relies on.

• Free plan. Duet is free to download. On the free plan you can keep two PDFs in your Library at a time, with its Canvas and the other features shown as free in the app. We may change what the free plan includes in a future version. If we do, you won’t lose content you’ve already created.
• Duet Pro. Duet Pro is an optional, one-time, non-consumable in-app purchase. It unlocks the features described on the purchase screen, which are currently unlimited PDFs and Canvases, all six themes and Home Screen widgets. It isn’t a subscription and it doesn’t renew. We may add more features to Duet Pro, but we don’t promise any specific future feature.
• Price. The price that applies is the one shown on the purchase screen before you confirm, in your local currency and including any taxes the App Store applies. Prices vary by country.
• Payment. Apple processes purchases through your App Store account, and Apple’s terms govern billing. RevenueCat confirms the purchase with Apple so Duet can unlock Pro.
• Restoring and other devices. Duet Pro is linked to the Apple Account you used to buy it. To unlock it on another iPhone, iPad or iPhone Duo signed in to that account, or after reinstalling, tap Restore Purchases in Settings or on the purchase screen. Where we’ve enabled it, you can share Duet Pro through Family Sharing.
• Refunds. Apple processes App Store purchases and refund requests. You can request a refund at reportaproblem.apple.com. Refund eligibility is decided under Apple’s policies and your rights under applicable law. If a purchase is refunded, Duet Pro features turn off. Your documents and Canvases stay on your device.
• Price changes. We may change the price of Duet Pro. A change never affects a purchase you’ve already made.

Duet runs on iPhone, iPad and iPhone Duo with iOS 27 or iPadOS 27 or later. The layout depends on your screen. For example, the side-by-side Canvas needs a larger screen such as iPad or the inner display of iPhone Duo, fold-aware layouts are only on iPhone Duo, and Apple Pencil works on iPad. AI features need a device that supports Apple Intelligence. Use the free plan to check that Duet works on your device before you buy Duet Pro.

We may update, change or stop offering any part of Duet. We may update these Terms. When we do, we’ll post the new version at this address and change the “Last updated” date. If we make a material change, we’ll tell you in the app before it takes effect. If you keep using Duet after a change takes effect, you accept the updated Terms. A change to these Terms doesn’t take away Duet Pro features you’ve already paid for, unless the law or Apple requires it.

You can stop using Duet at any time by deleting it. Your licence ends automatically if you seriously breach these Terms. Sections 2, 3, 4, 6 and 9 to 13 continue to apply after termination. Termination doesn’t affect any rights you have under applicable law.

Duet and Duet Pro are provided “as is” and “as available”. To the fullest extent the law allows, we disclaim all warranties, whether express or implied, including warranties of merchantability, fitness for a particular purpose and non-infringement. We don’t promise that the app will be error-free or uninterrupted, or that AI output will be accurate.

Nothing in these Terms limits rights you have as a consumer that can’t be excluded by law, including your rights under India’s Consumer Protection Act, 2019, where it applies.

To the fullest extent the law allows, we aren’t liable for indirect, incidental, special or consequential damages, or for loss of data, profits or goodwill, arising from your use of Duet.

Our total liability to you for all claims relating to Duet is limited to the greater of:

• (a) the total amount you paid for Duet Pro; or
• (b) US$50.

These limits don’t apply to liability that can’t be limited by law, such as liability for fraud, gross negligence, or death or personal injury caused by negligence. They also don’t reduce statutory consumer remedies you’re entitled to.

These Terms are governed by the laws of India. Disputes are subject to the non-exclusive jurisdiction of the courts of Delaware, USA. If you are a consumer, you also keep any protections given to you by the mandatory laws of the country where you live.

These Terms are between you and us, not Apple. In addition:

(a) Responsibility. We, not Apple, are solely responsible for Duet, Duet Pro and their content.

(b) Licence scope. Your licence is limited to use on Apple-branded products you own or control, as permitted by the Usage Rules in the App Store Terms of Service.

(c) Maintenance and support. We are solely responsible for maintenance and support. Apple has no obligation to provide any.

(d) Warranty. If Duet fails to meet any applicable warranty, you may notify Apple, and Apple will refund the purchase price, if any. To the extent the law allows, Apple has no other warranty obligation for the app. We are responsible for any other claims, losses, liabilities, damages, costs or expenses caused by a failure to meet a warranty.

(e) Product claims. We, not Apple, are responsible for any claims by you or a third party relating to Duet. This includes product liability claims, claims that the app fails to meet a legal or regulatory requirement, and claims under consumer protection, privacy or similar laws.

(f) Intellectual property. If a third party claims that Duet infringes their intellectual property rights, we, not Apple, are responsible for investigating, defending, settling and discharging that claim.

(g) Legal compliance. You confirm that you are not located in a country subject to a US Government embargo or designated as a “terrorist supporting” country. You also confirm that you are not on any US Government list of prohibited or restricted parties.

(h) Third-party terms. You must comply with any applicable third-party terms when you use Duet.

(i) Contact. Questions, complaints or claims about the app go to us at deepanshi@consciousengines.com, 251 Little Falls Drive, Wilmington, Delaware 19808, USA.

(j) Third-party beneficiary. Apple and its subsidiaries are third-party beneficiaries of these Terms. Once you accept these Terms, Apple has the right to enforce them against you as a third-party beneficiary.

deepanshi@consciousengines.com