Last updated: June 26, 2026
This page explains what Klar ("Klar", "we", "us") collects when you use klar.princebloom.com, and why.
1. Guest mode
In guest mode, no account is needed. Your level, streak, and progress are stored only in your own browser (local storage). We do not receive or store this data on our servers.
2. Information we collect with an account
If you create an account, we collect:
- Email address and a username (email sign-up), or your name, email, and profile photo from Google (Google sign-in);
- Your learning activity: streaks, spaced-repetition review state, exam results, and grammar weakness logs, so the app can track your progress and show it back to you;
- Basic technical data needed to operate the service (such as request logs from our hosting provider).
We do not collect payment information today, as Klar has no paid tier yet.
3. How we use your information
We use account data to authenticate you, sync your progress across devices, calculate your streak and spaced-repetition schedule, and show you where you are making mistakes by grammatical category. We do not sell your data or use it for advertising.
4. Service providers
We rely on a small number of providers to run Klar:
- Supabase: authentication, database storage of your profile and learning data;
- Google: optional sign-in via Google OAuth, used only to authenticate you;
- Cloudflare: hosting and content delivery for the site itself.
These providers process data on our behalf under their own security and privacy commitments. We do not share your data with anyone else.
5. Vocabulary and content data
The German vocabulary, example sentences, and reading texts you see are openly licensed third-party data (Tatoeba, Wiktionary via Kaikki) or original content we wrote. This is separate from your personal data; see data/ATTRIBUTION.md for source attribution.
6. Cookies and local storage
We use local storage and a session token (set by Supabase) to keep you signed in. We do not use third-party advertising or tracking cookies.
7. Data retention and deletion
We keep your account data for as long as your account exists. You can ask us to delete your account and associated data at any time by contacting us at the email below.
8. Children's privacy
Klar is not directed at children under 13. We do not knowingly collect personal information from children under 13.
9. Security
Authentication and data storage are handled by Supabase over encrypted connections. No online service can guarantee perfect security, but we do not implement any custom storage of passwords ourselves; that is handled entirely by Supabase Auth.
10. Your rights
You can request a copy of your data or ask us to delete your account at any time by emailing us. If you signed in with Google, you can also revoke Klar's access from your Google account settings.
11. Changes to this policy
We may update this policy as the product evolves. Material changes will be reflected by an updated date at the top of this page.
12. Contact
Questions about this policy, or requests to access or delete your data, can be sent to princebloomton@gmail.com.