Privacy Policy

Effective date: July 30, 2026  ·  Last updated: September 15, 2026

This Privacy Policy explains how StringAI (the “App”), operated by Joshua Vigel, an individual (“StringAI,” “we,” “us,” or “our”), collects, uses, shares, and protects information when you use the App. By using StringAI, you agree to this Policy and to our Terms of Service.

1. Who we are

StringAI is a mobile application that analyzes musical-instrument practice (starting with violin) and provides coaching. The App is owned and operated by Joshua Vigel, an individual, based in the State of Texas, United States. We are the “data controller” for the information described here. You can reach us at joshvigel@gmail.com.

2. Children & age requirement

StringAI is not directed to children under 13, and we do not knowingly collect personal information from anyone under 13. You must be at least 13 years old to create an account or use the App. If you are between 13 and the age of majority in your jurisdiction, you may use StringAI only with the involvement and consent of a parent or legal guardian.

If you believe a child under 13 has provided us personal information, contact joshvigel@gmail.com and we will delete it promptly. We do not sell the personal information of minors, and we do not knowingly process it for advertising.

3. Information we collect

a. Information you provide

• Account information — your email address and a password (passwords are stored only in salted, hashed form by our authentication provider; we never see your plain-text password).
• Profile & practice inputs — instrument, skill level, goals, and the title/composer of pieces you enter. If you upload a piece of sheet music (e.g., a PDF), we store that file so you can reuse it.
• Support communications — messages you send us and the contact details in them.

b. Practice recordings (processed on your device)

When you record or upload a practice session, StringAI captures video and audio of your playing. This raw video and audio is analyzed on your device. We do not upload your raw practice video or audio to our servers. Recordings are stored locally on your device, and only a limited number of recent recordings are retained there (older ones are automatically deleted).

c. Analysis data (derived on device, stored in your account)

From the on-device analysis we generate non-media data such as: per-note pitch and timing values, tone and rhythm measurements, body/hand position keypoints (numeric coordinates — not images), metric scores, detected patterns, and the resulting written coaching. This derived data (typically a few kilobytes per session) is associated with your account so you can see your history and progress.

d. Subscription & purchase information

If you buy a subscription, the purchase is processed by Apple or Google through their in-app purchase systems, and managed for us by our subscription provider (RevenueCat). We receive your subscription status and a purchase/transaction identifier. We do not collect or store your credit-card or payment-card number — that is handled by the app store.

e. Device & usage information

• Technical data — device type, operating-system version, app version, and a randomly generated app/user identifier, used to operate and troubleshoot the App.
• Push notification token — if you enable notifications, a device token used to deliver practice reminders.
• Diagnostics — basic crash and error information to keep the App working.

We do not currently use third-party advertising networks, and we do not track you across other companies’ apps and websites for advertising.

4. Camera, microphone & photos

StringAI requests these device permissions only for their stated purpose:

• Camera — to record your playing so posture and bow technique can be analyzed.
• Microphone — to capture your sound so intonation, tone, and rhythm can be analyzed.
• Photo library — only if you choose to upload an existing practice video.
• Notifications — only if you opt in to practice reminders.

You can revoke any of these permissions at any time in your device settings; some features will stop working without them.

5. Artificial intelligence disclosure

StringAI uses artificial intelligence (AI) to help produce your coaching. We want to be transparent about this, consistent with U.S. Federal Trade Commission (FTC) guidance on AI and honest advertising.

• What is AI-generated. The written coaching, explanations, exercise suggestions, and any chat responses in the App are generated in whole or in part by an automated AI system (a third-party large language model). They are produced by software, not by a human music teacher reviewing your session.
• What we send to the AI. To generate coaching, we send the AI provider a small, structured summary of your session — for example, which technical patterns were detected, your metric trends, and the piece’s style. We do not send your raw practice video or audio to the AI provider.
• Our AI provider. AI coaching is generated by a third-party large language model (currently DeepSeek V4), run for us by our inference providers Hugging Face and DeepInfra and accessed only through our secure server. The session summary we send contains no name, email address, account identifier, video, audio, or images. We do not sell your data to any AI company.
• Accuracy & limitations. AI can be wrong. Its measurements and advice are estimates and may contain errors, may not fit your specific situation, and are not a substitute for a qualified music teacher or for professional, medical, or physical-therapy advice. Do not rely on StringAI for any decision where an error could cause injury or harm. See our Terms of Service for the full disclaimer, including guidance on avoiding physical strain or injury.
• No consequential automated decisions. StringAI’s AI does not make legal, financial, employment, or similar decisions about you. It provides practice feedback only.

6. Data collection summary (privacy “nutrition” label)

The table below summarizes the categories of data associated with StringAI, in the style of an app-store privacy label. “Linked to you” means the data is associated with your account or identity. We do not use any of this data to track you across other companies’ apps or websites.

Data type	Collected?	Linked to your identity?	Purpose	Used to track you?
Contact info (email)	Yes	Yes	Account creation, login, support	No
User content — practice video & audio	Processed on device; not collected by our servers	Stays on your device	On-device analysis of your playing	No
User content — sheet music / files you upload	Yes	Yes	Let you store & reuse pieces	No
Derived analysis data (scores, notes, keypoints, coaching)	Yes	Yes	Show results, track progress	No
Identifiers (user/app ID)	Yes	Yes	Operate the App, sync your history	No
Purchases / subscription status	Yes	Yes	Manage your subscription	No
Payment card number	No (handled by Apple/Google)	—	—	No
Usage & diagnostics	Yes	Limited	Reliability, troubleshooting	No
Location, contacts, browsing history, advertising data	No	—	—	No

This summary is provided for transparency and to mirror app-store disclosures. If any practice changes, we will update both this table and our app-store privacy label.

7. How we use information

• To provide the App’s core function — analyzing your practice and generating coaching and progress tracking.
• To create and secure your account and authenticate you.
• To manage subscriptions and enforce free-tier limits.
• To send you notifications you’ve opted into.
• To maintain, troubleshoot, and improve the App.
• To respond to your support requests.
• To comply with law and enforce our Terms of Service.

We rely on your consent (for optional permissions like camera, microphone, photos, and notifications) and on our legitimate interest in operating and improving the App and performing our agreement with you.

8. How we share information

We do not sell your personal information and we do not share it for cross-context behavioral advertising. We share information only with service providers who help us run the App, and only as needed for them to perform their service for us:

Provider	Purpose	Data involved
Supabase	Cloud hosting, database, authentication, file storage	Account info, derived analysis data, uploaded files
Hugging Face & DeepInfra (DeepSeek model)	Generating AI coaching text	Non-identifying session summary (no raw video/audio)
RevenueCat	Subscription management	Subscription status, purchase identifiers
Apple App Store / Google Play	App distribution & payment processing	Purchase transactions (handled by the store)
Expo (push service)	Delivering notifications you opt into	Push token

We may also disclose information (a) to comply with law, legal process, or a valid government request; (b) to enforce our Terms or protect the rights, safety, or property of StringAI, our users, or the public; or (c) in connection with a merger, acquisition, or sale of assets, in which case we will notify you of any change in how your information is handled.

9. Data retention & deletion

• Raw recordings live only on your device and a limited number of recent sessions are kept locally; older recordings are deleted automatically, and you can delete them at any time.
• Account & derived data is kept while your account is active. You can delete your account in the App’s settings, which removes your associated data from our systems, subject to reasonable backup and legal-retention windows.
• To request deletion by email, contact joshvigel@gmail.com.

10. Your privacy rights

Depending on where you live (including under the California Consumer Privacy Act (CCPA/CPRA) and similar U.S. state laws, and the EU/UK GDPR), you may have the right to:

• access or receive a copy of the personal information we hold about you;
• correct inaccurate information;
• delete your information;
• opt out of “sale” or “sharing” of personal information (note: we do not sell or share your personal information);
• not be discriminated against for exercising these rights.

To exercise any right, email joshvigel@gmail.com. We will verify your request (typically by confirming control of your account email) and respond within the time required by law. You may use an authorized agent where the law allows.

11. Security

We use reasonable technical and organizational measures to protect your information, including encryption in transit, hashed passwords, access controls, and keeping raw recordings off our servers. No method of transmission or storage is 100% secure, however, and we cannot guarantee absolute security. You are responsible for keeping your login credentials confidential.

12. Where your data is processed

StringAI is operated from the United States, and our service providers may process and store information in the United States and other countries. If you access the App from outside the United States, you understand your information may be transferred to, stored, and processed in the U.S., where data-protection laws may differ from those in your country.

13. Copyright & DMCA takedown

We respect intellectual-property rights and expect our users to do the same. StringAI lets users enter piece titles and, in some cases, upload files such as sheet music. You are responsible for ensuring you have the rights to any content you upload or use in the App.

If you believe content stored or made available through StringAI infringes your copyright, you may send a notice under the U.S. Digital Millennium Copyright Act (17 U.S.C. § 512) to our designated agent:

Your notice must include: (1) a physical or electronic signature of the copyright owner or authorized agent; (2) identification of the copyrighted work claimed to be infringed; (3) identification of the material claimed to be infringing and information reasonably sufficient to locate it; (4) your contact information; (5) a statement that you have a good-faith belief the use is not authorized by the owner, its agent, or the law; and (6) a statement, under penalty of perjury, that the information in your notice is accurate and that you are the owner or authorized to act on the owner’s behalf.

Counter-notice. If your content was removed and you believe it was removed in error, you may submit a counter-notice with the information required by § 512(g). Repeat infringers may have their accounts terminated. Submitting a materially false notice or counter-notice may make you liable for damages, including costs and attorneys’ fees.

14. Disclaimer of warranties (“as is”)

We work hard to describe our data practices accurately and to protect your information, but we cannot promise perfection. TO THE FULLEST EXTENT PERMITTED BY LAW, THE APP AND ALL PRIVACY-RELATED FEATURES — INCLUDING ON-DEVICE PROCESSING, DATA STORAGE, SECURITY MEASURES, ACCOUNT AND DATA DELETION, DATA-EXPORT AND ACCESS REQUESTS, CONSENT AND PERMISSION CONTROLS, AND ANY AI-GENERATED OUTPUT — ARE PROVIDED “AS IS” AND “AS AVAILABLE,” WITH ALL FAULTS AND WITHOUT WARRANTY OF ANY KIND.

WE DISCLAIM ALL WARRANTIES, EXPRESS, IMPLIED, OR STATUTORY, INCLUDING IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE, AND NON-INFRINGEMENT. WITHOUT LIMITING THAT, WE DO NOT WARRANT THAT: (a) THE APP OR OUR SERVICE PROVIDERS’ SYSTEMS WILL BE SECURE, UNINTERRUPTED, OR FREE OF ERROR, LOSS, CORRUPTION, OR UNAUTHORIZED ACCESS; (b) YOUR DATA WILL BE PRESERVED, BACKED UP, OR RECOVERABLE; (c) DELETION WILL REACH EVERY BACKUP, LOG, OR ARCHIVE IMMEDIATELY; (d) TRANSMISSIONS WILL BE PRIVATE OR FREE OF INTERCEPTION; OR (e) ANY MEASUREMENT, SCORE, OR AI-GENERATED COACHING WILL BE ACCURATE, COMPLETE, OR SUITABLE FOR YOU.

As stated in Section 11, no method of transmission or storage is 100% secure. SOME JURISDICTIONS DO NOT ALLOW CERTAIN WARRANTY EXCLUSIONS, SO SOME OF THE ABOVE MAY NOT APPLY TO YOU, AND NOTHING HERE LIMITS ANY WARRANTY OR RIGHT THAT CANNOT BE EXCLUDED UNDER APPLICABLE LAW — INCLUDING YOUR RIGHTS UNDER APPLICABLE DATA-PROTECTION LAW, WHICH THIS SECTION DOES NOT WAIVE.

15. Limitation of liability

TO THE FULLEST EXTENT PERMITTED BY LAW, IN NO EVENT WILL STRINGAI (JOSHUA VIGEL) BE LIABLE FOR ANY INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL, EXEMPLARY, OR PUNITIVE DAMAGES, OR FOR ANY LOSS OF PROFITS, REVENUE, DATA, GOODWILL, OR PRIVACY, ARISING OUT OF OR RELATING TO THIS POLICY OR TO THE COLLECTION, USE, STORAGE, SHARING, DISCLOSURE, LOSS, OR DELETION OF YOUR INFORMATION — INCLUDING ANY UNAUTHORIZED ACCESS TO OR ALTERATION OF YOUR DATA, ANY ACT OR OMISSION OF A THIRD-PARTY SERVICE PROVIDER LISTED IN SECTION 8, OR ANY RELIANCE ON AI-GENERATED OUTPUT — WHETHER BASED ON WARRANTY, CONTRACT, TORT (INCLUDING NEGLIGENCE), STRICT LIABILITY, OR ANY OTHER LEGAL THEORY, AND EVEN IF WE HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

TO THE FULLEST EXTENT PERMITTED BY LAW, OUR TOTAL AGGREGATE LIABILITY FOR ALL CLAIMS ARISING OUT OF OR RELATING TO THIS POLICY OR YOUR INFORMATION WILL NOT EXCEED THE GREATER OF (A) THE AMOUNT YOU PAID US IN THE 12 MONTHS BEFORE THE EVENT GIVING RISE TO THE CLAIM, OR (B) US $100. This cap is shared with, and not additional to, the limitation of liability in our Terms of Service — the two documents together are subject to a single aggregate cap, not one per document.

SOME JURISDICTIONS DO NOT ALLOW THE EXCLUSION OR LIMITATION OF CERTAIN DAMAGES, SO SOME OF THE ABOVE MAY NOT FULLY APPLY TO YOU. NOTHING IN THIS SECTION EXCLUDES OR LIMITS LIABILITY FOR FRAUD, FRAUDULENT MISREPRESENTATION, WILLFUL MISCONDUCT, GROSS NEGLIGENCE, DEATH OR PERSONAL INJURY CAUSED BY OUR NEGLIGENCE, OR ANY OTHER LIABILITY THAT CANNOT LAWFULLY BE LIMITED — INCLUDING ANY STATUTORY REMEDY AVAILABLE TO YOU UNDER APPLICABLE DATA-PROTECTION LAW. THESE LIMITATIONS ARE A FUNDAMENTAL BASIS OF THE BARGAIN BETWEEN US AND APPLY EVEN IF A LIMITED REMEDY FAILS OF ITS ESSENTIAL PURPOSE.

16. Indemnification

To the fullest extent permitted by law, you agree to indemnify, defend, and hold harmless StringAI (Joshua Vigel) from and against any third-party claims, demands, investigations, damages, liabilities, losses, fines, penalties, and expenses (including reasonable attorneys’ fees and costs) arising out of or related to:

• Content and data you supply — any information, recording, file, or sheet music you record, upload, or enter into the App, including any claim that it infringes a third party’s intellectual-property or privacy rights;
• Other people in your recordings — your recording, uploading, or processing of any person other than yourself (for example, a teacher, accompanist, or family member) without their informed consent, or without the consent of a parent or guardian where that person is a minor;
• Your breach — your violation of this Policy, our Terms of Service, or any applicable law, including data-protection, privacy, wiretapping, biometric-privacy, or recording-consent laws;
• Misuse of your account — activity under your account resulting from your failure to keep your credentials confidential; and
• False requests — any privacy request you submit under Section 10 on behalf of someone else without authority to do so.

We may assume the exclusive defense and control of any matter subject to indemnification by you, at your expense, in which case you agree to cooperate with our defense. You may not settle any such matter in a way that imposes any obligation or admission on us without our prior written consent. This obligation does not apply to the extent a claim arises from our own violation of law or from conduct for which liability cannot lawfully be shifted to you, and it survives termination of your account.

17. Termination & suspension

Your right to terminate. You may stop using StringAI at any time. You may revoke camera, microphone, photo, or notification permissions in your device settings; delete locally stored recordings on your device; and delete your account from the App’s settings or by emailing joshvigel@gmail.com. Withdrawing consent or deleting your account does not affect the lawfulness of processing carried out before you did so.

Our right to terminate or suspend. We may suspend or terminate your account and your access to the App, in whole or in part, with or without notice, if: (a) you breach this Policy or our Terms of Service; (b) you are a repeat copyright infringer under Section 13; (c) we reasonably believe your account is being used unlawfully, fraudulently, or in a way that risks harm to you, other users, or us; (d) we are required to do so by law, regulation, or a valid legal request; or (e) we discontinue the App or any part of it. Where practical and lawful, we will give advance notice — and for discontinuation of the App we will give reasonable notice and an opportunity to export your data.

What happens to your data. On termination, your account and the derived analysis data associated with it are deleted from our active systems, subject to the reasonable backup and legal-retention windows described in Section 9. Raw recordings are unaffected because they never left your device — you control their deletion. We may retain a minimal record of the termination, and any information we are required to keep by law or need to keep to resolve a dispute, enforce our agreements, or prevent fraud or abuse. Anonymized or aggregated data that can no longer be linked to you may be retained.

Survival. Termination does not end obligations that by their nature should continue. Sections 14 (warranties), 15 (liability), 16 (indemnification), this Section 17, and 18 (governing law, disputes & arbitration) survive termination of your account and any deletion of your data, along with any other provision that by its nature should survive.

18. Governing law, disputes, arbitration & class-action waiver

Governing law. This Policy and any dispute, claim, or controversy arising out of or relating to it, to your privacy, to your data, or to your use of the App (a “Dispute”) are governed by the laws of the State of Texas, United States, without regard to its conflict-of-laws rules, and by the U.S. Federal Arbitration Act as to arbitration. The dispute-resolution provisions of our Terms of Service are incorporated here by reference; if this Section and that Section conflict, the Terms of Service control. This choice of law does not deprive you of the protection of any mandatory consumer or data-protection law of your country or state of residence that cannot be varied by agreement.

Informal resolution first. Before starting arbitration, you agree to email us at joshvigel@gmail.com with a description of your Dispute and to give us 60 days to try to resolve it informally. This step is a condition of starting arbitration, and the applicable limitations period is tolled while it runs.

Binding arbitration. If we cannot resolve a Dispute informally, it will be resolved by final and binding arbitration administered by the American Arbitration Association (AAA) under its Consumer Arbitration Rules, on an individual basis, before a single arbitrator, seated in the State of Texas (you may request a telephonic or video hearing, or a hearing in your home county, where the AAA rules allow). The arbitrator has exclusive authority to resolve any dispute about the interpretation, applicability, or enforceability of this arbitration agreement, except that a court — not the arbitrator — decides whether the class-action waiver below is enforceable. You and we are each giving up the right to a trial by jury and to appeal, except on the narrow grounds the Federal Arbitration Act allows.

Class-action waiver. To the fullest extent permitted by law, you and StringAI each agree to bring claims against the other only in an individual capacity, and not as a plaintiff or class member in any purported class, collective, consolidated, private-attorney-general, or representative proceeding. The arbitrator may not consolidate more than one person’s claims or preside over any form of representative or class proceeding, and may award relief only in favor of the individual party seeking it and only to the extent needed to satisfy that party’s individual claim.

Exceptions. Either party may (a) bring an individual claim in a small-claims court with jurisdiction, or (b) seek injunctive or other equitable relief in court to protect intellectual-property or data rights. For any Dispute not subject to arbitration, you and we consent to the exclusive jurisdiction and venue of the state and federal courts located in Texas, and each waives any objection to that forum. Nothing here prevents you from filing a complaint with, or seeking relief from, a data-protection authority, attorney general, or other government agency.

30-day opt-out. You may opt out of this arbitration agreement and class-action waiver by emailing joshvigel@gmail.com with the subject “Arbitration Opt-Out,” including your name and account email, within 30 days of first accepting this Policy. Opting out affects only this arbitration agreement; the rest of the Policy still applies, and opting out will not disadvantage you in any other way.

Severability & survival. If any portion of this Section is found unenforceable, the remainder stays in effect, except that if the class-action waiver is found unenforceable, this entire arbitration Section will be void and any Dispute will proceed in the courts identified above. This Section survives termination of your account and any deletion of your data.

19. Changes to this Policy

We may update this Policy from time to time. When we do, we will change the “Last updated” date above and, for material changes, provide a more prominent notice in the App. Your continued use of StringAI after an update means you accept the revised Policy.

20. Contact

Questions, requests, or privacy concerns:

Joshua Vigel — StringAI
Email: joshvigel@gmail.com
State of Texas, United States