Legal

Terms of sale and use

Effective October 6, 2026

These terms apply when you buy eOctavo, use this website, install apps from the store, or submit an app. They're short; please read them.

On this page: Buying eOctavo · Installing · Store apps · Warranty and liability · Submission terms · Copyright complaints

Buying eOctavo

When you buy eOctavo you get a personal, non-transferable licence to install and use the eOctavo firmware on Xteink X3 devices that you own. Updates are free: each new version can be downloaded from your purchase page.

The full licence is in LICENSE.txt in the download. In short: please don't share, resell or publish the download or the firmware, and don't reverse-engineer it except where the law allows. The open-source parts of eOctavo come with their own licences, listed in THIRD-PARTY-NOTICES.txt, and nothing here limits your rights under them.

Payment is processed by Stripe, at the price shown on this site. You can have a full refund within 30 days: see the refund policy.

eOctavo is independent software. It isn't made by, affiliated with or endorsed by Xteink. Xteink and X3 are trademarks of their owner.

Installing

Installing eOctavo replaces the firmware on your X3, using the Windows installer and the X3's cable. The installer doesn't touch the books and files on your SD card, and if an install fails the X3 keeps its previous firmware so you can try again. We don't currently provide a way to put Xteink's original firmware back, so install eOctavo only if you're happy to keep using it (the 30-day refund still applies). Xteink's own warranty and support may not cover an X3 running other firmware.

Store apps

Apps in the store are free. Some are made by eOctavo and others by independent authors, who are responsible for their apps. We check every app before it's listed and apps run in a sandbox, but we can't promise that every app is free of mistakes. Apps that use the internet get their information from services run by other people.

Using this website

Please don't try to break into, overload or disrupt the site, or use it to send anything harmful.

Warranty and liability

We want eOctavo to work well and we'll try to fix problems you tell us about. Beyond that, and as far as the law allows, eOctavo, the store apps and this website are provided "as is", without any other warranties, and we aren't liable for indirect or consequential losses, or for lost data. Keep copies of anything important on your SD card. As far as the law allows, our total liability to you is limited to the amount you paid for eOctavo.

Nothing in these terms excludes or limits rights you have under consumer law that can't be excluded or limited, or our liability for anything that can't be limited by law, such as death or personal injury caused by negligence, or fraud.

Submission terms

These terms apply when you send an app through the submit form.

• You keep ownership. Your app stays yours. These terms only give eOctavo the permissions it needs to run the store.
• What you let us do. You give eOctavo a worldwide, non-exclusive, royalty-free licence to host, copy, distribute and display your app and its listing (name, description, icon, art and screenshots) on this website, in the store and on X3 devices; to adapt it for the store, for example by re-encoding pictures, making the X3's picture packs, banners and screenshots, and tidying the listing text; and to use the app's name, art and screenshots to promote the store and eOctavo.
• Free for everyone. Anyone may install and use your app from the store for free.
• What you promise. You made the app or have the right to share it on these terms. It doesn't infringe anyone else's copyright, trademark or other rights, and its name doesn't include someone else's trademark. Anything in it made by others (code, art, fonts, text or data) is licensed for this use and credited in the app or its description. It contains nothing hateful, sexual, misleading or harmful.
• Removal. You can ask us to take your app out of the store at any time by emailing support@eoctavo.com. Copies already installed on X3s stay until their owners remove them, and promotional material already published can stay up. We may decline, remove or change the listing of any app at any time.

How we handle your email address and the rest of a submission is described in the privacy policy.

Copyright or trademark complaints

If you believe something on this site or in the store infringes your copyright or trademark, email support@eoctavo.com with:

1. the work or trademark you say is being infringed;
2. where the material is (the address of the app's page or file);
3. your name, postal address, phone number and email address;
4. a statement that you believe in good faith that the use isn't authorised by the owner, its agent or the law;
5. a statement that the information in your notice is accurate and, under penalty of perjury, that you are the owner or authorised to act for the owner;
6. your physical or electronic signature.

We'll look into it, remove or disable the material where that's right, and let the app's author know so they can respond.

Changes and contact

If we change these terms we'll update this page and the date at the top; the terms in force when you bought eOctavo apply to that purchase. Questions about these terms go to support@eoctavo.com.