Privacy Policy

What we collect

If you create an account, we store your email address and a hashed password (managed by Supabase Auth). We never see or store your plain-text password.

If you connect your WaniKani account, we store your WaniKani API key to fetch your study data. You can disconnect and delete this key at any time from your account settings.

When you run a simulation, we store the input parameters and results (anonymized) in an aggregate cache to improve performance. Paid users additionally have a personal simulation history.

Session tracker (optional)

If you install the optional Itsumade session tracker userscript, it sends session start time, end time, review count, and lesson count to our servers. No item-level data, answers, or personal information beyond your study pattern is collected. The session tracker is entirely optional and can be removed at any time by uninstalling the userscript.

Payments

Payments are processed by Gumroad. We never see or store your credit card number. Gumroad handles all payment data under their own privacy policy.

Cookies and tracking

We use a session cookie for authentication and a cookie consent preference cookie to remember your tracking choices.

We use Google Tag Manager and Google Analytics 4 to understand how the site is used: page views, feature usage, and general traffic patterns. No advertising or remarketing features are enabled. Analytics data is collected under Google's own privacy policy. You can opt out of analytics tracking via the cookie banner.

We do not use advertising cookies, tracking pixels, or any third-party marketing tools.

Data sharing

We do not sell or rent your personal data. The third parties that process data on our behalf are Supabase (database/auth), Gumroad (payments), and Google Analytics (anonymized usage analytics).

Data deletion

To delete your account and all associated data, please contact us. We will process deletion requests within 30 days. You can disconnect your WaniKani API key and remove the session tracker at any time from your account settings without deleting your account.