Privacy Policy

Effective Date: October 6, 2026

At 4th Density Ventures, we take your privacy seriously. This policy explains how we collect, use, and protect your information when you use our application (Scholar Stack) and related services.

1. Information We Collect

  • Personal Information: We collect minimal personal information, primarily your email address if you choose to create an account.
  • Study Materials: To provide our core services, we process audio recordings, text, and images you upload ("Study Materials").
  • Usage Data: We collect anonymized data on how you interact with the app (e.g., features used, session duration) to improve our algorithms and user experience.

2. How We Use Information

  • AI Processing: Study Materials are processed by AI models (Google Gemini) to build outlines, flashcards, quizzes, maps, translations, recaps and other study aids.
  • Lecture Transcription: On-device transcription keeps lecture audio on your phone. If you choose cloud transcription, the recording is sent to AssemblyAI to be turned into text.
  • Spoken Exam Answers: When you answer an oral exam question out loud, the audio is sent once to Google Gemini for grading and is never stored — not in our databases, our file storage, or our logs. We keep only the text of your answer and your score.
  • Grading Checks: Some grading decisions are double-checked by TypeSafe (Jev), which receives text only.
  • Study Songs: Song lyrics are sent to a music service (Google Lyria or ElevenLabs) to render the song. The finished song is saved to your account.
  • Homework Photos and Links: Photos you send to Homework Help and web pages you import are processed to produce study material; the photo itself is not kept.
  • Subscription Management: We use RevenueCat to process and manage your subscription status. We never see your card details.

3. Age Verification and Facial Images

Some memory aids use a more adult register and are available only to verified adults. Verifying your age is entirely optional — you can use every other part of Scholar Stack without it — and it works as follows:

  • Device biometrics: your device confirms it is you using Face ID or Touch ID. This happens entirely on your device. We never receive your fingerprint or face data from this step.
  • Age estimation: if you continue, a single photo of your face is sent to Google’s Gemini service, which estimates only whether the person shown is an adult.
  • The photo is never stored.It is held in memory for the length of that one request and is not written to our databases, our file storage, or our logs. We keep only the outcome — a true/false flag and the date it was recorded.
  • No facial recognition or identification is performed. The image is not used to identify you, is not compared against any other image, and is not used to train any model.

4. Data Storage and Security

  • We use Firebase for secure data storage.
  • Study Materials are encrypted and stored in secure cloud environments.
  • We do not sell your personal data to third parties.

5. Third-Party Services

Scholar Stack uses the following service providers. Each receives only what it needs to do its job:

  • Firebase / Google Cloud: Sign-in and data storage.
  • Google Gemini: Study aid generation, grading, speech, and optional age estimation from a facial image that is never stored (see section 3).
  • AssemblyAI: Cloud lecture transcription, only when you choose it.
  • ElevenLabs: Study song rendering.
  • TypeSafe: Text-only grading checks.
  • RevenueCat: Subscription and payment management.
  • Sentry: Performance monitoring and crash reporting.

We do not allow these providers to sell your data. Your Study Materials are not used to train our own models.

6. Your Rights

You can delete your account and all associated Study Materials at any time via the "Academic Profile" settings in the app. Deleting a lecture, song or recap removes it from our storage.

7. Contact Us

For privacy-related inquiries, please contact: support@getscholarstack.com