Privacy Policy

Last updated: December 18, 2025

Introduction

BrainDen ("we," "our," or "us") operates https://www.brainden.app (the "Service"). This Privacy Policy explains how we collect, use, disclose, and safeguard your information when you use our Service.

By using the Service, you agree to the collection and use of information in accordance with this policy.

Information We Collect

Personal Information

When you sign up for our waitlist or create an account, we collect:

  • Email address
  • Payment information (processed securely via Stripe or other payment processors)

Study Content

When you use the app, we collect and store:

  • Voice recordings and transcriptions
  • Notes, flashcards, and study materials you create
  • Quiz responses and learning progress
  • Interactions with our AI tutor (Feynman Mode)

Usage Data

We automatically collect:

  • Device information (type, operating system, browser)
  • Usage statistics (features used, time spent, session data)
  • IP address and general location

How We Use Your Information

We use your information to:

  • Provide and maintain the Service
  • Process your study materials and generate AI-powered content
  • Send you app updates, launch notifications, and account information
  • Improve our AI models and Service features
  • Analyze usage patterns to enhance user experience
  • Detect and prevent fraud or abuse
  • Comply with legal obligations

Data Security

We implement industry-standard security measures to protect your data:

  • All data is encrypted in transit (HTTPS/TLS)
  • Stored data is encrypted at rest
  • Payment information is processed through Google Play's secure payment systems (PCI DSS compliant)
  • Regular security audits and monitoring
  • Access controls limit who can view your data

However, no method of transmission over the internet is 100% secure. While we strive to protect your data, we cannot guarantee absolute security.

Third-Party Services

We use the following third-party services:

  • Google Play - In-app purchases (Android)
  • OpenAI/Anthropic - AI processing (flashcard generation, Feynman Mode)
  • Whisper AI - Voice transcription
  • Cloud hosting providers - Data storage and infrastructure

These services have their own privacy policies. Your study content may be processed by AI services but is not used to train third-party models without your consent.

Data Retention

We retain your personal information and study content for as long as your account is active or as needed to provide the Service. If you delete your account, we will delete your data within 30 days, except:

  • Data required for legal compliance or dispute resolution
  • Aggregated, anonymized data used for analytics
  • Backup copies (deleted within 90 days)

Your Rights

You have the right to:

  • Access - Request a copy of your personal data
  • Correction - Update inaccurate or incomplete data
  • Deletion - Request deletion of your account and data
  • Export - Download your study materials in a portable format
  • Opt-out - Unsubscribe from marketing emails (account emails will still be sent)

To exercise these rights, contact us at hello@feynmannurse.app

Children's Privacy

Our Service is not intended for users under 18 years old. We do not knowingly collect personal information from children. If you believe we have collected data from a minor, please contact us immediately.

California Privacy Rights (CCPA)

If you are a California resident, you have additional rights under the California Consumer Privacy Act:

  • Right to know what personal information is collected
  • Right to know if personal information is sold or disclosed
  • Right to opt-out of sale (we do not sell your data)
  • Right to deletion
  • Right to non-discrimination for exercising your rights

International Users

Your information may be transferred to and processed in the United States or other countries where our service providers operate. By using the Service, you consent to this transfer.

Changes to This Policy

We may update this Privacy Policy from time to time. We will notify you of significant changes by email or through a prominent notice in the app. Your continued use of the Service after changes constitutes acceptance of the updated policy.

Contact Us

If you have questions about this Privacy Policy, contact us: