Terms of use

Last updated 25 October 2026. By installing or using ZenTrain Studio ("the app"), or by ticking "I agree" when the app first opens, you agree to these terms, to our Privacy policy and to the Health and safety information, which are part of these terms. If you do not agree, please do not use the app. "We" and "us" mean Blackridge Engineering, LLC, doing business as ZenTrain Studio, the publisher of the app. Please read sections 11 (Assumption of risk and release) and 14 (Indemnification) carefully: they limit your right to make claims against us and make you responsible for some claims against us.

1. Who may use the app

You must be at least 13 years old. If you are under 18, or under the age of majority where you live, a parent or guardian must agree to these terms for you and supervise your use. A parent or guardian who accepts these terms for a minor agrees to them both personally and on the minor's behalf, including the release in section 11 and the indemnity in section 14, and is responsible for the minor's use of the app. Please read the Health and safety information first.

2. Your licence

We give you a personal, non-exclusive, non-transferable licence to use the app on devices you own or control, for your own non-commercial use, under these terms and the rules of the store or website you got it from. You may not copy, sell, rent or redistribute the app or remove its notices. The open-source parts of the app (listed in Licenses and credits) are licensed to you under their own licences, and nothing in these terms limits the rights those licences give you.

3. Your account

Some features may need an account (when sign-in is available). Keep your sign-in secure: you are responsible for what is done with your account. Use one account per person, give a name and profile that do not mislead, and tell us if you think someone else is using your account. We may change or reclaim a name or @handle that impersonates someone or breaks these terms.

4. Your sessions, recordings and Notate entries

What you create belongs to you. Sessions you build, your settings and your Notate entries are kept on your phone; you are responsible for keeping your own copies. Audio you download from the app is yours to listen to and to share for non-commercial purposes; each file starts with a short "Created with ZenTrain Studio" spoken intro, which you may not remove. Ask us before using downloaded audio commercially.

5. What you share: Resonate, links, profiles, comments and posts

When you publish a session to Resonate, create a share link, fill in a public profile, or post a comment or an article (where the app or zentrainstudio.com offers it), you keep ownership of it, and you give us and other users a free, worldwide licence to store, show, play, copy and attune (remix) it within the app and on zentrainstudio.com for as long as it is published. You can unpublish or delete it at any time. You must have the right to share everything in it. Do not share anything that is illegal, hateful, harassing, sexual, violent, misleading about health, an infringement of someone else's rights, spam, or that impersonates another person. What other users share is their own: we do not check it before it appears.

6. Our right to remove content and suspend accounts

We may, at our sole discretion and without notice or refund (except where the law requires one), remove or hide any session, profile, comment, post or other creation, and suspend, restrict or end any account, device or user's access to the app's online features, if we decide that the account, behaviour or shared creations break these terms or abuse the app, its community or its services in any way.

7. Using the app and our servers as intended

You may use the app, zentrainstudio.com and our servers only in the ways they are meant to be used. You may not reverse engineer, decompile, disassemble, modify, hack, manipulate or tamper with the app, its sound engine, its servers or their data; access them by automated means or in any way other than through the app and website as intended; attack, overload, scrape or misuse Resonate, share links or our servers; or try to get around their limits or security. The only exceptions are what the law or the open-source licence of a part of the app expressly allows (see Licenses and credits). Online services (Resonate, share links, accounts and content updates) may change, pause or end; the app keeps working on your phone without them.

8. Our names and logos

ZenTrain Studio, ZenTrain Studio Pro, the brainwave logo (the brain with headphones) and the app's other names, logos and designs are the intellectual property of Blackridge Engineering, LLC (ZenTrain Studio), as are the app's software, sound engine, sessions, texts and design (apart from the open-source parts named in Licenses and credits). You may not use them without our written permission, except to name the app accurately.

9. Purchases

If the app offers paid features, they are sold through the app store you use or through our website, at the price shown there. The store's refund rules, or the refund terms shown when you buy from our website, apply, along with any rights you have under your local consumer law.

10. Health disclaimer

The app is not a medical device and gives no medical advice. You use it at your own risk and are responsible for following the Health and safety information, including keeping the volume at a safe level.

11. Assumption of risk and release

Listening to sound, binaural beats, isochronic tones, guided voice, breathing patterns and vibration is an activity you choose to do, and it carries risks, including those described in the Health and safety information: for example dizziness, headaches, drowsiness, anxiety or other changes in how you feel; effects on people with epilepsy, seizure disorders, heart conditions, mental health conditions or other medical conditions; harm if you listen while driving or doing anything that needs your attention; and hearing damage from loud or prolonged listening. You use the app voluntarily, and you knowingly assume all of these risks, known and unknown.

TO THE FULLEST EXTENT PERMITTED BY LAW, YOU RELEASE, WAIVE AND FOREVER DISCHARGE BLACKRIDGE ENGINEERING, LLC, DOING BUSINESS AS ZENTRAIN STUDIO, AND ITS MEMBERS, MANAGERS, OFFICERS, EMPLOYEES, CONTRACTORS, AGENTS, LICENSORS, SUCCESSORS AND ASSIGNS (THE "ZENTRAIN PARTIES") FROM ANY AND ALL CLAIMS, DEMANDS, LIABILITIES, DAMAGES, LOSSES, COSTS AND EXPENSES OF ANY KIND, KNOWN OR UNKNOWN, ARISING OUT OF OR RELATED TO YOUR USE OF THE APP, ITS SESSIONS AND SOUNDS, ITS ONLINE SERVICES OR ANYTHING OTHER USERS SHARE, INCLUDING CLAIMS FOR PERSONAL INJURY, ILLNESS, HEARING LOSS, EMOTIONAL DISTRESS, DEATH, PROPERTY DAMAGE OR LOSS OF DATA, AND INCLUDING CLAIMS BASED ON THE ZENTRAIN PARTIES' OWN NEGLIGENCE. This release does not cover gross negligence, wilful misconduct or fraud, or any liability that the law does not allow to be released.

If you live in California, you waive California Civil Code section 1542, which says: "A general release does not extend to claims that the creditor or releasing party does not know or suspect to exist in his or her favor at the time of executing the release and that, if known by him or her, would have materially affected his or her settlement with the debtor or released party." You also waive any similar law of any other state or country.

12. No warranty

The app and its services are provided "as is" and "as available", without warranties of any kind, as far as the law allows. We do not promise that they will be free of errors, always available, or that they will have any particular effect on you.

13. Limitation of liability

As far as the law allows, Blackridge Engineering, LLC (ZenTrain Studio) does not bear responsibility for, or accept liability for:

sessions, profiles, comments, posts or anything else published by other users;
damage to your hearing, or to your headphones, speakers, phone or other equipment, caused by prolonged or loud listening, misuse or overuse;
harm caused by a technical glitch, a software bug, an interruption of the app or its services, or any other incidental, consequential or personal damage arising from using the software;
loss of data, or indirect or special losses.

Our total liability to you is limited to the amount you paid for the app in the twelve months before the claim (or 50 US dollars if that is more). Nothing in these terms limits liability that cannot be limited by law, or your rights as a consumer.

14. Indemnification

You agree to defend, indemnify and hold harmless the ZenTrain Parties from and against any claims, actions, demands, liabilities, damages, losses, settlements, costs and expenses (including reasonable attorneys' fees and court costs) brought or claimed by anyone, arising out of or related to: (a) your use or misuse of the app, its sessions or its online services; (b) anything you create, publish or share, including sessions, profiles, comments and posts; (c) your breach of these terms or of the Health and safety information; (d) your violation of any law, or of anyone else's rights, including intellectual property, privacy and publicity rights; or (e) use of the app through your account or device by anyone you allow, including a minor in your care. We may take over the defence and control of any matter you must indemnify us for, at your expense, and you will cooperate with us in it. You may not settle any such matter without our prior written consent.

15. Ending these terms

You can stop at any time by uninstalling the app (and deleting your account, if you have one). We may end your use of the online services if you break these terms. Sections 4, 5 (for what is already shared), 8, 10 to 14, 16 and 17 continue after that.

16. Disputes

Please contact us first; most problems can be solved quickly. These terms are governed by the laws of the State of Texas, USA, unless the law where you live gives you protections that cannot be taken away.

17. General

These terms, the Privacy policy and the Health and safety information are the whole agreement between you and us about the app and its services. If a court finds any part of these terms unenforceable, that part is enforced as far as the law allows and the rest stays in effect. If we do not enforce a right straight away, we have not given it up. You may not transfer your rights or duties under these terms; we may transfer ours, for example to a company that takes over the app. We keep a record that you agreed to these terms (when, which version, and on which installation of the app), as described in the Privacy policy.

18. Changes

We may update these terms. We will show the date of the last update here and, for important changes, tell you in the app before they apply, and we may ask you to agree again. Using the app after that means you accept them.

Contact

ZenTrain Studio · office@zentrainstudio.com