BrainFlow

BrainFlow Privacy Policy

Last updated: October 24, 2025

BrainFlow (“we”, “us”, “our”) is a private voice-to-notes app. This policy explains what we process, why, and how to contact us.

Data Controller: An individual based in the United Kingdom
Contact: hello@brainflow.tech

Our Privacy Promise

  • We don’t sell your data or use it for behavioral advertising.
  • Audio is sent only to provide transcription, then deleted.
  • We avoid collecting personal data unless you choose to provide it.

Summary (TL;DR)

  • Audio: Sent securely to our processors to create a transcript, then deleted after processing.
  • Identifiers: We use a hashed, app-scoped device identifier to deliver results, prevent abuse, and support product analytics. When you grant App Tracking Transparency (ATT) consent we also receive the Apple IDFA/Google GAID (where available) and Adjust device identifiers for attribution and fraud prevention. Declining ATT limits measurement to the hashed ID only.
  • Marketing attribution: With ATT consent, Adjust measures installs, trials, and purchases and may forward conversion events to Meta/Facebook for aggregated campaign reporting. No attribution data is used to target individual ads.
  • Notes & transcripts: Stored on your device. You control export and deletion.
  • Lightweight analytics (PostHog, Cloud US) for events only — includes basic app lifecycle events (app start, foreground/background) and is not used for behavioral advertising or profiling.

Data We Process

Processed locally on your device

  • Voice recordings you create
  • Transcripts/notes and any edits you make
  • App preferences and settings

Sent off-device for processing (temporarily)

When you request a transcription:

  • Your audio file is uploaded via our infrastructure to a transcription provider.
  • The provider generates text and returns it to the app.
  • Audio and intermediate data are deleted by the provider after processing.

Attribution & revenue analytics (Adjust)

When you opt into tracking via Apple’s ATT prompt (or equivalent platform controls), we enable Adjust to measure installs, trials, and purchases so we can understand campaign performance.

  • Events: install, trial_start, and purchase events with associated price, currency, app store, SKU, and a deduplication ID.
  • Identifiers: Adjust device IDs and, where available, the Apple IDFA or Google GAID. Declining ATT prevents us from receiving these identifiers.
  • Diagnostics: Device model, OS version, locale, IP address (shortened where provided by the platform), timestamps, and other technical metadata required by Adjust’s Privacy Manifest to detect fraud and ensure accurate attribution.

Adjust deduplicates events and flags suspected fraud. With ATT consent, Adjust forwards trial and purchase conversion callbacks to Meta/Facebook (App ID 1086586876764224) so we can measure campaign performance. The data is aggregated and not used for behavioral advertising toward individual users.

What we do not collect

  • Name, email, or contact details (unless you voluntarily contact us)
  • Location data
  • Advertising identifiers if you decline ATT or reset your device’s identifier
  • Behavioral profiling or advertising analytics

Identifiers

  • Hashed device identifier (app-scoped install/device ID, hashed before analytics) used to route jobs, prevent abuse, and group product analytics events.
    • Not linked to your identity and not used for cross-app tracking.
  • Adjust device identifier to link installs and conversion events for aggregated attribution and fraud prevention.
  • Advertising identifiers (IDFA/GAID) only if you grant ATT consent. You can withdraw consent at any time through device settings, which stops cross-app tracking for attribution.

Cross-app tracking occurs only after you tap “Allow” on the ATT prompt. Declining means attribution relies solely on the hashed, app-scoped identifier and certain campaign reports become less precise.

Why We Use Your Data (Purposes)

  • App functionality: Transcribe audio, structure notes, and return results to your device.
  • Reliability & abuse prevention: Ensure the service works and isn’t misused (rate limiting, error diagnosis, fraud prevention).
  • Product analytics: Understand feature usage to improve quality and reliability. Events only — no session replay, heatmaps, or autocapture. Includes app lifecycle events (app start, foreground/background).
  • Marketing attribution (with consent): Measure campaign performance and revenue impact via Adjust and Meta/Facebook when you allow tracking. Used only for aggregated reporting, not to target individual ads.

Legal Bases (UK GDPR)

  • Performance of a contract (Art. 6(1)(b)): To provide the transcription/notes service you request.
  • Legitimate interests (Art. 6(1)(f)): To keep the service secure, prevent fraud, and understand usage via limited product analytics events (no session replay/heatmaps). We use the minimum data necessary and do not use it for marketing without your consent.
  • Consent (Art. 6(1)(a)): To access advertising identifiers, enable Adjust attribution, and share conversion data with Meta/Facebook. You can withdraw consent in device settings or by contacting us.

Third-Party Services (Processors)

We use trusted processors only to deliver core functionality:

  • Railway – hosting/infrastructure to relay processing jobs.
  • Deepgram – speech-to-text transcription. Deepgram processes audio to produce text and deletes audio after processing.
  • XAI via Openrouter – text refinement.
  • PostHog (Cloud US) – product analytics (events only). We send event names (including basic app lifecycle events such as app start and foreground/background) and basic app/device metadata (e.g., app version and a hashed app-scoped device ID). No audio, transcripts, or notes are sent. Data is not used for advertising.
  • Adjust (EU & US infrastructure) – install, campaign, and revenue attribution plus fraud prevention. Receives hashed install identifiers, Adjust device IDs, ATT-authorized advertising identifiers, device/diagnostic data, and install/trial/ purchase events (price, currency, store, SKU, deduplication ID). Adjust deduplicates events and provides aggregated reporting.
  • Meta/Facebook (via Adjust callbacks) – acts as Adjust’s sub-processor for campaign measurement and receives trial_start and purchase conversion events tied to Facebook App ID 1086586876764224 when you grant ATT consent. Used solely for aggregated campaign measurement; no behavioral advertising.
  • App Stores (Apple, Google) – billing and app distribution.

Processors act under our instructions. We configure them to avoid retaining your content beyond what’s necessary to complete your request.

Data Retention & Deletion

  • On device: Your recordings and notes remain on your device until you delete them.
  • On servers: Audio is held only long enough to complete processing, then deleted. We don’t keep server-side copies of your content.
  • Support emails: If you contact us, we keep your message only as long as needed to respond and comply with legal obligations.
  • Analytics: Product analytics events are retained for up to 12 months.
  • Attribution data: Adjust retains event and device data for up to 24 months (their default) for attribution and fraud prevention. We can request earlier deletion on your behalf.

Opt-out options:

  • Respond to Apple’s ATT prompt; you can change your choice later under Settings > Privacy > Tracking (iOS) or the equivalent Android controls.
  • Reset or disable your advertising identifier in device settings (“Reset Advertising Identifier”, “Delete Advertising ID”).
  • Contact us at hello@brainflow.tech to disable Adjust for your device or request deletion of prior attribution data.
  • Visit Adjust’s opt-out page for platform-specific instructions.
  • Meta/Facebook measurement stops if you decline ATT or revoke tracking permission in device settings.

Security

  • All transfers use HTTPS/TLS.
  • App data is stored in your device’s secure storage.
  • Access to processing systems is protected by authentication and least-privilege controls.
  • We monitor compliance with Apple and Google store policies for tracking, including ATT prompts and declared tracking domains/data types.

App Store Disclosures

  • We display Apple’s App Tracking Transparency prompt before enabling Adjust or Meta tracking and respect whichever choice you make.
  • Our App Store privacy nutrition label and Google Play Data Safety forms list the tracking domains (e.g., adjust.com, facebook.com) and data types described in this policy.

International Transfers

Our processors may handle data in the US and/or EU/UK. Adjust processes data in EU and US data centers under its Data Processing Agreement and Standard Contractual Clauses. Meta/Facebook processes conversion data in the United States under Standard Contractual Clauses and related safeguards. Analytics data sent to PostHog Cloud US is stored in the United States. Where required, we rely on appropriate safeguards (e.g., Standard Contractual Clauses).

Your Rights

You can:

  • Access/export your notes (from the app).
  • Delete recordings and transcripts (from the app).
  • Object or restrict processing by not initiating transcription.
  • Opt out of analytics/attribution: Contact us to disable PostHog and Adjust for your device and request deletion of prior analytics or attribution events. An in-app toggle is not currently available.
  • Questions or complaints? Email hello@brainflow.tech. You may also lodge a complaint with your local data protection authority.

Children’s Privacy

BrainFlow is not intended for children. We do not knowingly process children’s data.

Changes to This Policy

If we make material changes, we’ll update the “Last updated” date and, where appropriate, notify you in-app at least 30 days before changes take effect.

Contact

Questions or requests: hello@brainflow.tech

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