Privacy Policy — blueberry

This describes what blueberry collects, why, and how it's stored. If you're using Guest mode (no account), almost none of this applies — your data stays in your browser's local storage and is never sent to us.

1. What we collect

Data	Why
Email, first/last name, password (hashed by our auth provider, Supabase — we never see it in plain text)	Create and secure your account
Phone number (optional)	Only if you choose to add it in Account > Security
Goal score, target test date, self-reported/manual test scores	Personalize your dashboard and (if you use it) your study plan
Practice test and drill history — which questions you answered, whether you got them right, how long you spent	Show your progress, stats, and mistake review; compute per-skill accuracy
Saved/bookmarked questions, imported custom tests, in-progress session state	Let you resume where you left off across devices
AI Tutor conversation history	So your tutor chats are there when you come back
Subscription status (active/inactive), via Stripe	Know whether to apply Pro limits or free limits
"Report a problem" submissions	Let us fix bad questions/explanations
Contact form submissions — the name, email, and message you send us	Reply to you and keep a record of the conversation

2. What we don't do

We don't sell your personal data.
We don't run advertising or ad-tracking on the Service.
We don't share your practice history or AI Tutor conversations with anyone outside the service providers listed below.

3. Who processes your data (subprocessors)

Provider	Purpose
Supabase	Database, authentication, and account storage
Cloudflare	Hosting the website and its backend (Workers)
Stripe	Payment processing for the Pro subscription — we never see or store your card number
Anthropic (Claude)	Generates AI explanations and AI Tutor responses. The text of your question/conversation is sent to Anthropic's API to generate a reply; see Anthropic's own privacy policy for how they handle API data.
Google Fonts, jsDelivr (CDN), Desmos	Load fonts, library code (KaTeX math rendering, the Supabase client), and the embedded graphing calculator. These load directly from the provider when you use the site, which means your browser makes a request to their servers (mainly your IP address and browser info, standard for loading anything from a CDN).

4. Cookies and local storage

blueberry doesn't use tracking or advertising cookies. It uses your browser's local storage (not cookies, though they're often grouped together) to remember your theme (light/dark), sidebar preference, and — in Guest mode — your entire practice history, entirely on your device. See our Cookie Notice for the full list.

5. How long we keep data

We keep your account data for as long as your account exists. If you delete your account (Account > Security > Delete account), we permanently delete your profile, history, saved questions, custom tests, and tutor conversations. Some records tied to billing (e.g. Stripe transaction records) may be retained separately by Stripe as required for tax/accounting purposes, independent of your blueberry account.

6. Your choices

Access/export: your practice history and stats are visible in-app at any time (My Stats, Recent Attempts).
Correction: you can edit your name, goal score, test date, and manual scores directly in Account settings.
Deletion: Account > Security > Delete account permanently removes your data as described above.
Guest mode: you can use most of the app's features without ever creating an account or sending us any personal data.

7. Children's privacy

blueberry is intended for users 13 and older, consistent with our Terms of Service. We don't knowingly collect personal information from children under 13.

8. Changes to this policy

If we make a material change to what we collect or how we use it, we'll make a reasonable effort to notify active accounts before the change takes effect.

9. Contact

Questions about this policy, or a request to access or delete your data, can go to support@blueberrysat.com or through our contact form.