Privacy Policy

1. Introduction

SignCascade UD ("we", "us", or "our") respects the privacy of users of our services (the "Service") and is committed to protecting personal information. This Privacy Policy explains what information we collect and how we use it.

1.1 Applicable Services

This policy applies to the following services:

• Our website (signcascade-ud.jp)
• Manabi Palette (free educational tools, games, and printable materials)
• Shunsoku Master (IT Passport exam preparation app)
• Koe Palette (AAC assistive app)
• Other applications and web services provided by us

2. Information We Collect

We may collect the following information to provide and improve our services.

2.1 Information You Provide

• Email address when contacting us
• Survey responses
• Feedback and feature requests

2.2 Automatically Collected Information

Data Type	Purpose	Source
Device Identifier (Advertising ID)	Ad optimization	Google AdMob
Device Information (OS, model)	Compatibility verification & ad optimization	Google AdMob

2.3 Firebase Analytics

This app uses Firebase Analytics, provided by Google, to analyze usage patterns within the app and improve our service.

Firebase Analytics automatically collects the following information:

• Screen navigation history within the app
• Start, completion, and results of learning stages
• Quiz responses and accuracy rates
• Learning achievements such as medals earned and consecutive study days
• Operation history such as settings changes and feedback submissions

This information does not identify users as individuals. For details, please refer to the Firebase Privacy Policy and Google Privacy Policy.

2.4 Firebase Crashlytics

This app uses Firebase Crashlytics, provided by Google, to improve app quality and fix bugs. When the app terminates unexpectedly (crash), the following information is automatically sent:

• Internal app state at the time of crash (stack trace)
• Device model, OS version, and app version
• Date and time of the crash

This information does not identify users as individuals and is used solely to improve app stability.

2.5 In-App Feedback Feature

This app includes a "Report a typo" feature for reporting errors in questions or explanations, and an optional survey. When you send either, the following is transmitted to our endpoint (Google Apps Script) and stored in a Google Sheet we manage:

• Where the error is (question format, question ID), the type of error (chosen from a list), and details (free text you enter; optional)
• Your survey answers (multiple-choice items, free text, and a recommendation score)
• Date and time of submission
• The app name
• An anonymous device ID

The anonymous device ID is a random value generated on your device the first time you send something. It is used only so that a report and a survey answer sent from the same device can be read together. It is unrelated to your name, email address, or advertising ID, and you cannot be identified from it.

This feature does not ask for your email address. It does not send your name, contact details, or location. Both the report and the survey are optional, and every feature of the app remains available if you never send one. What you send is used only to correct the question data and improve the app. We are unable to reply.

2.6 Locally Stored Information

The following information is stored only on your device and is not transmitted to our servers:

• Learning progress and scores
• App settings (theme, notifications, etc.)
• Study streak data
• In-app purchase status (purchase flags and timestamps)
  * If linked with a Google account, this data is also stored in Firebase (see §2.8)

2.7 In-App Purchase Information

Some features of this app include paid features that can be purchased through Google Play Store billing. We handle in-app purchase information as follows:

• We do not directly obtain or store credit card numbers, bank account information, or other payment details. This information is managed under the responsibility of Google Play Store.
• After a purchase is completed, we use purchase tokens and timestamps issued by Google Play to verify and restore purchase status.
• Purchase status (whether purchased and purchase timestamps) is stored on your device.
• Purchase restoration after device changes is performed through Google Play Store's purchase history via your Google account.

For details, please refer to the Google Privacy Policy.

2.8 Firebase Authentication and Cloud Firestore

This app uses Firebase Authentication and Cloud Firestore, provided by Google, for cross-device purchase restoration and account management.

2.8.1 Anonymous Authentication

When the app is first launched, Firebase Authentication automatically generates an anonymous user ID. This ID is used only for internal app processing and does not contain any personally identifiable information. No login or account registration is required.

2.8.2 Google Account Linking (Optional)

You may optionally link your Google account from the Settings screen. When linked, the following information is stored in Firebase:

• Google account email address
• Google account display name

Account linking is optional. All app features are available without linking.

2.8.3 Data Stored in Cloud Firestore

The following information is stored in Firebase Cloud Firestore (Google servers) via encrypted communication:

• In-app purchase status (purchase flags and timestamps)
• Free trial start date
• Authentication method (anonymous / Google)
• Last active timestamp

This data is used solely for cross-device purchase restoration and account management. It is stored securely under your authentication credentials (UID) and cannot be accessed by other users.

2.8.4 Sign Out and Data Deletion

Signing out from the Settings screen will unlink your Google account and generate a new anonymous account. To request deletion of data stored in Firebase, please follow the procedure in §12.

3. How We Use Information

We use the collected information only for the following purposes:

1. Providing and maintaining the App's functionality
2. Bug fixes and service improvements
3. Responding to inquiries
4. Displaying advertisements
5. Creating usage statistics and analysis
6. Notifying about new features and updates
7. Processing in-app purchases and managing purchase status
8. Account management and cross-device purchase restoration

4. Disclosure to Third Parties

We do not disclose your personal information to third parties except in the following cases:

• With your consent
• When required by law
• When necessary to protect life, body, or property

4.1 Third-Party Services We Use

Service	Provider	Purpose	Privacy Policy
Google AdMob	Google LLC	In-app ad delivery	Link
Google Analytics 4 (GA4)	Google LLC	Website analytics	Link
Firebase Analytics	Google LLC	In-app usage analysis	Link
Firebase Crashlytics	Google LLC	App crash reporting	Link
Google Play Billing	Google LLC	In-app purchase payment processing	Link
Firebase Authentication	Google LLC	User authentication (anonymous & Google Sign-In)	Link
Cloud Firestore	Google LLC	Cloud sync of purchase status	Link
Google Apps Script / Google Sheets	Google LLC	Receiving and storing typo reports and survey answers	Link

5. Data Storage Location

• Your Device: Learning progress, settings, purchase status (available offline)
• Firebase (Google Servers): Authentication info, purchase sync data (see §2.8; protected by encrypted communication)
• Google Apps Script / Google Sheets (managed by us): typo reports and survey answers
• Inquiries: these reach us by email and remain in our mail service

6. Data Retention Period

• Inquiry content: 3 years after resolution

7. Your Rights

You have the following rights:

• Right of Access: Request disclosure of collected personal information
• Right of Rectification: Request correction of inaccurate information
• Right of Erasure: Request deletion of personal information
• Opt-out: Reset or disable advertising ID in device settings

8. Advertising

8.1 In-App Advertising

The App displays advertisements through Google AdMob. Your advertising ID may be used to deliver interest-based advertisements.

Advertisements are not displayed during study sessions or quiz questions.

If you do not wish to receive personalized ads, you can limit ad tracking in your device settings.

8.2 Website Advertising

Our website may use third-party advertising services (Google AdSense). Advertising providers may use cookies to display interest-based advertisements.

You can disable personalized ads on Google's Ad Settings page.

8-2. Cookies and Local Storage

Our website uses cookies and browser local storage (localStorage) for the following purposes:

• Theme settings: Saves your light/dark mode preference
• Tool settings: Saves settings for timers, scoreboards, and other tools
• Analytics: Uses Google Analytics 4 cookies for anonymous site usage analysis

Information stored in localStorage is kept only in your browser and is not transmitted to our servers. You can delete it at any time through your browser settings.

9. Children's Privacy

The App is intended for users aged 13 and older. We do not knowingly collect personal information from children under 13. If we discover that personal information from a child under 13 has been collected, we will promptly delete it.

10. Security

We implement appropriate technical and organizational measures to protect your information from unauthorized access, loss, or disclosure. However, no internet transmission is completely secure, and we cannot guarantee 100% security of your information.

10.1 Encryption in Transit

All communications between this app or site and our servers are encrypted using SSL/TLS (HTTPS). This prevents third parties from intercepting transmitted information.

11. Changes to This Policy

We may update this Privacy Policy as necessary. If there are significant changes, we will notify you within the App. Continued use of the App after changes constitutes acceptance of the revised policy.

12. Data Deletion Requests

You may request deletion of your data related to our service using the following method:

1. Send an email to contact@signcascade-ud.com with the subject line "Data Deletion Request".
2. Within a reasonable period, we will process the deletion of the following data:
   • Firebase Authentication account information (anonymous ID and linked Google account info)
   • Data stored in Cloud Firestore (purchase status, profile information)
   • Anything you sent as a typo report or a survey answer, including the anonymous device ID
   • Usage data recorded in Firebase Analytics
   • Information linked to Google AdMob advertising IDs (we will forward the deletion request to Google)

Note that the app itself stores user data (learning progress, dictionary bookmarks, etc.) only on the device, and all such data is deleted when the app is uninstalled.

13. Contact Us

For questions or comments about this Privacy Policy, please contact us at: