Terms of use

Updated: 20 October 2026

These terms are an agreement between you and Lê Bá Trọng, an individual developer publishing as USelf Labs (“USelf Labs”, “we”), for your use of the LeziBook app, the lezibook.uselflabs.com website and related services (“LeziBook”). By using LeziBook you accept these terms and the Privacy policy.

1. What LeziBook is

LeziBook is a tool to manage, read and listen to books you provide yourself. Opening files, preparing text and making the voice happen on your phone. LeziBook does not sell, distribute or store book content on its servers.

2. Content you bring

• You confirm that you have the legal right to every file you import: DRM-free books you bought, public-domain books, books under a licence that allows it, or your own documents.
• You are responsible for that content. We do not see it, review it or keep a copy.
• Audio LeziBook makes from your books is for your own listening on the device. You may not use LeziBook to make recordings for distribution, sale or publication of content you have no rights to.

3. DRM and copyright protection

LeziBook refuses DRM-protected files and has, and will have, no way to remove DRM. You may not use LeziBook to circumvent, remove or disable technical protection measures of any content.

4. Voices and third-party components

Downloadable voices are provided under each voice’s and model’s own licence; credits and licences are in the app (Settings › Voices and models, Open-source licences). Voices are synthetic and may misread some sentences; LeziBook does not guarantee how every sentence is read.

5. Licence to use the app

We grant you a personal, non-exclusive, non-transferable, revocable licence to install and use LeziBook on devices you own or control, under these terms and the rules of the App Store or Google Play. You may not:

• reverse-engineer, modify or redistribute the app, except where the law allows;
• use LeziBook’s servers through excessive automation, overload them or attack them;
• use LeziBook for unlawful purposes or to infringe others’ rights.

6. Accounts (when available)

The app is fully usable without an account. If you sign in with Apple or Google to sync, you are responsible for keeping that account secure. You can delete your account at any time in the app.

7. Paid plan (when available)

• Monthly or yearly plans are bought and renew automatically through the App Store or Google Play, at the price shown at purchase.
• Cancel renewal in the App Store or Google Play subscription settings; deleting the app or your account does not cancel the plan.
• Refunds follow Apple’s or Google’s policy.
• Plans include a monthly AI text clean-up allowance (for example a number of pages); when it runs out, the app falls back to on-device rule-based normalization.
• Listening to your own books with on-device voices is never locked behind the paid plan.

8. AI text clean-up (when available)

This feature runs only when you turn it on for a book. Passages are sent through our server to Google Gemini for processing and are not stored (see the Privacy policy). The AI may only fix formatting and write numbers and abbreviations out as words; it must not summarise or change the meaning. When a result fails our automatic checks, the app keeps the original text. We do not guarantee perfect results.

9. Launch waitlist

Submitting your email on lezibook.uselflabs.com means you agree to receive one email when the app is in the stores. Your email is deleted afterwards.

10. Changes and discontinuation

We may update, change or discontinue parts of LeziBook. Reading and listening on the device are designed to work without our servers; if a server service ends, we will try to give reasonable notice.

11. No warranty

LeziBook is provided “as is”. To the extent the law allows, we do not warrant that it is error-free, always available or fit for a particular purpose.

12. Limitation of liability

To the extent the law allows, we are not liable for indirect damage, loss of data on your device, or damage arising from content you bring. Our total liability does not exceed what you paid for LeziBook in the 12 months before the event. Nothing here excludes liability that the law does not allow to be excluded, including consumer rights.

13. Termination

You can stop using LeziBook at any time by uninstalling it (and deleting your account if you have one). We may end your access to server services if you seriously breach these terms.

14. Governing law

These terms are governed by the law of Vietnam. Disputes are first settled by negotiation; failing that, by the court that has jurisdiction under Vietnamese law. This does not take away your rights as a consumer.

15. Changes to these terms

When the terms change we update the date at the top; important changes are announced in the app before they take effect. Continuing to use LeziBook after the effective date means you accept the new version.

16. Contact

support@uselflabs.com · Lê Bá Trọng (USelf Labs), Ho Chi Minh City, Vietnam