Last updated: February 16, 2026

Overview

Keyoku ("the App") is a flashcard study app. This Privacy Policy explains how we collect, use, and protect your information.

Information We Collect

Account Information

When you sign in with Apple or Google, we receive basic profile information provided by those services (such as your name and email address). You may also use the App anonymously without providing any personal information.

Usage Analytics

We use Firebase Analytics and Mixpanel to collect anonymized usage data, such as:

• Which screens you visit
• Which features you use (e.g., creating decks, studying flashcards)
• App performance and crash data
• Device type and operating system version

This data helps us understand how the App is used and improve the experience. Analytics data is not linked to your identity in a way that would allow us to identify you personally.

Content You Create

Flashcard decks and their content are stored in Firebase Firestore and on your device. This data is associated with your account so it can sync across your devices.

How We Use Your Information

• To provide and maintain the App
• To sync your flashcard data across devices
• To understand usage patterns and improve the App
• To send study reminders (only if you enable notifications)