Last updated: April 29, 2026
Koji ("we," "our," or "us") operates the Koji mobile application. This Privacy Policy explains how we collect, use, and protect your information when you use our app.
When you create an account, we collect your email address and display name. If you sign in with Apple or Google, we receive the name and email associated with that account. We do not collect passwords directly as authentication is handled by Firebase Authentication.
We collect lesson progress data, including completed lessons, accuracy scores, XP earned, and streak information. This data is stored in Firebase Firestore and linked to your account.
We use your information to provide and improve the Koji learning experience. This includes saving your progress across devices, tracking your learning streaks, managing your subscription status, and personalizing your experience.
Koji uses the following third-party services:
Firebase (Google) for authentication and data storage. Google AdMob for displaying advertisements to free users. RevenueCat for managing subscriptions. ElevenLabs for audio pronunciation files (processed offline, no user data sent). Each of these services has its own privacy policy governing how they handle data.
Free users may see ads served by Google AdMob. AdMob may collect device identifiers and usage data to serve relevant ads. Premium subscribers do not see ads. You can opt out of personalized advertising through your device settings.
Subscription purchases are processed through Apple's App Store. We do not collect or store payment information. RevenueCat manages subscription status on our behalf. You can manage or cancel your subscription in your App Store account settings.
Your data is stored securely using Firebase, which uses industry-standard encryption in transit and at rest. We do not sell, rent, or share your personal information with third parties for marketing purposes.
Koji is suitable for users of all ages. We do not knowingly collect personal information from children under 13 without parental consent. If you believe a child under 13 has provided us with personal information, please contact us and we will delete it.
You can request deletion of your account and all associated data by contacting us at the email below. Upon request, we will delete your account, progress data, and any personal information within 30 days.
We may update this Privacy Policy from time to time. We will notify you of any changes by posting the new policy in the app and updating the "Last updated" date above.
If you have questions about this Privacy Policy, please contact us at support@kojiapp.com.