Privacy Policy

Last updated: May 19, 2026

Build Your Flow is developed and operated by Kajinoha Studios, an independent developer based in Japan. This Privacy Policy explains how we collect, use, store, and protect your information when you use our app. Kajinoha Studios is not a registered company — "Kajinoha Studios" is a developer trade name.

For privacy matters, contact: buildyourflow.app@gmail.com

1. Information We Collect

We collect the following information when you create an account and use the app:

Email address — used to create and manage your account
User ID — a unique identifier assigned to your account by Firebase Authentication
User content and app activity — the sequences and clips you create within the app, stored in Cloud Firestore
Device identifiers and technical data — such as Firebase installation identifiers, device type, operating system, and performance metrics such as app start time and network request performance, used for app functionality, authentication, syncing, security, and technical performance monitoring

We do not intentionally collect your location, contacts, financial information, health information, or other sensitive personal information. Some technical information may be processed automatically by our service providers as necessary to operate, secure, and maintain the app.

Google account data (optional, only if you use YouTube playlist import) — if you choose to import a YouTube playlist, we request limited read-only access to your Google account's YouTube data via Google's OAuth authorization. This includes the titles, thumbnails, and video IDs of playlists and videos you select for import. This access is used solely to create sequences and clips within your own account and is never used for any other purpose.

2. How We Use Your Information

We use the information we collect to:

Create and manage your account
Save and sync your sequences and clips across sessions
Provide core app functionality
Monitor and improve app performance
Maintain the security of the app and prevent fraud

We do not use your information for advertising, marketing, or any purpose beyond operating the app.

3. Data Storage and Service Providers

We use the following Google Firebase services to operate the app:

Firebase Authentication — manages account creation and login
Cloud Firestore — stores your sequences, clips, and account data
Firebase Performance Monitoring — collects technical performance metrics including app start time, network request performance, device type, operating system, and Firebase installation identifiers, to help us maintain and improve the app
YouTube Data API (Google) — used only when you choose to import a YouTube playlist, to retrieve playlist and video metadata as described in Section 6

We do not sell your personal information. We do not share your personal information for advertising or cross-context behavioural advertising. We disclose limited personal information to service providers, such as Google Firebase, only as necessary to operate, secure, and maintain the app, or where required by law.

For more information on how Google handles data, please refer to Google's Privacy Policy at policies.google.com/privacy.

4. Data Retention

We keep your account data for as long as your account remains active. If you delete your account, we delete your account credentials, user ID, sequences, clips, and account-associated app data from our active systems. We aim to complete deletion requests within 30 days, unless a longer period is required or permitted by law.

Some limited technical data, such as performance metrics, security logs, or service provider records, may be retained by Google Firebase in accordance with Google's own retention policies or where required for security, legal, or operational reasons.

5. Video Content

Build Your Flow does not download, store, or reproduce any YouTube video content. All videos are played through YouTube's official embed player in accordance with YouTube's Terms of Service. Use of YouTube videos through the app may also be subject to YouTube's own Terms of Service and Privacy Policy at youtube.com/t/terms. We are not responsible for the content of videos accessed through the app.

6. YouTube Playlist Import

Build Your Flow offers an optional feature that allows you to import an existing YouTube playlist to automatically create a sequence. If you choose to use this feature, you will be asked to grant Build Your Flow read-only access to your YouTube account's playlists via Google's OAuth authorization (using the scope youtube.readonly).

When you use this feature, we access and store the following information from your YouTube account, limited to the playlists and videos you choose to import:

Playlist and video titles
Video IDs and thumbnail URLs
Playlist item counts and video durations

This information is used solely to automatically create sequences and clips within your own Build Your Flow account, and is stored in Cloud Firestore in the same manner as manually created clips and sequences. We do not access, store, or use any other data from your Google or YouTube account, and we do not share this information with any third party. You can revoke Build Your Flow's access to your Google account at any time via your Google Account settings at myaccount.google.com/permissions.

7. International Data Transfers

Your information may be processed in Japan, the United States, and other countries where our service providers operate. Google Firebase may process data in multiple regions. Where required by law, we rely on appropriate safeguards for international transfers of personal data.

8. Your Rights and Account Deletion

Depending on where you are located, you may have the right to access, correct, or delete your personal data.

To delete your account and account-associated data, you can do so directly within the app by going to Settings → Delete Account. This will permanently delete your account credentials, user ID, sequences, clips, and account-associated app data from our active systems. Some limited technical data may be retained by our service providers according to their own retention policies or where required for security, legal, or operational reasons.

We aim to respond to all privacy requests within 30 days. For any other privacy-related requests, contact us at buildyourflow.app@gmail.com.

9. Children's Privacy

Build Your Flow is not directed at children under the age of 13. We do not knowingly collect personal information from children under 13. If you believe a child has provided us with personal information, please contact us at buildyourflow.app@gmail.com and we will delete it promptly.

10. California Residents (CCPA / CPRA)

If you are a California resident, you have the following rights:

Right to know — you may request information about the personal information we collect, use, and disclose
Right to delete — you may request deletion of your personal information
Right to correct — you may request correction of inaccurate personal information
Right to opt out of sale or sharing — we do not sell or share your personal information for cross-context behavioural advertising
Right to limit use of sensitive personal information — we do not use or disclose sensitive personal information for purposes that would require a right to limit under California law
Right to non-discrimination — we will not discriminate against you for exercising any of these rights

To exercise your rights, contact us at buildyourflow.app@gmail.com.

11. European Users (GDPR)

If you are located in the European Economic Area, you have the following rights under the General Data Protection Regulation:

Right of access — request a copy of the personal data we hold about you
Right to rectification — request correction of inaccurate data
Right to erasure — request deletion of your personal data
Right to restrict processing — request that we limit how we use your data
Right to data portability — request your data in a portable format
Right to object — object to our processing of your personal data
Right to withdraw consent — where processing is based on consent, you may withdraw it at any time
Right to lodge a complaint — you have the right to lodge a complaint with your local data protection supervisory authority

Our legal bases for processing are performance of a contract, where processing is necessary to provide the app service, and our legitimate interests, where processing is necessary to maintain app security, troubleshoot issues, prevent fraud, and improve technical performance.

Since the developer is based in Japan, which holds an EU adequacy decision, and our service providers may process data internationally, we rely on appropriate safeguards for any transfers outside the EEA.

To exercise any of these rights, contact us at buildyourflow.app@gmail.com.

12. Japanese Users (APPI)

If you are located in Japan, you may request disclosure, correction, suspension of use, or deletion of your retained personal data in accordance with applicable Japanese privacy laws. To make a request, contact us at buildyourflow.app@gmail.com.

13. CalOPPA (California Online Privacy Protection Act)

In accordance with CalOPPA:

We post this Privacy Policy within the app and make it accessible via a direct link
This policy identifies the categories of personal information we collect and the third parties with whom it may be shared
Users may request review, correction, or deletion of their personal information by contacting buildyourflow.app@gmail.com or using the in-app account deletion feature
If we make material changes, we will provide notice within the app or by other appropriate means before the changes take effect where required by law
Our app does not currently respond to "Do Not Track" signals

14. Changes to This Policy

We may update this Privacy Policy from time to time. If we make material changes, we will provide notice within the app or by other appropriate means before the changes take effect where required by law. The date at the top of this policy reflects the most recent update.

15. Contact

For any questions, concerns, or privacy requests related to this Privacy Policy, please contact:

Kajinoha Studios — buildyourflow.app@gmail.com