Deep Practice Studio

Privacy Policy

Last Updated: March 10, 2026

TOMOSHIBI LLC ("we," "our," or "us") has established this Privacy Policy as follows regarding the handling of user information in Deep Practice Studio (the "App").

1. Information We Handle

The App handles the following information.

1.1 Information Entered or Added by Users

  • Information entered by users within the App, such as material titles, tags, and notes
  • YouTube URLs and YouTube playlist URLs
  • PDF, image, video, and audio files selected and imported by users

1.2 Information Generated by the App

  • Material settings such as practice order, start positions, end positions, and timer settings
  • Practice logs, including date and time, practice duration, completion status, and notes

1.3 Information the App Does Not Collect

At this time, the App does not collect user information for the following purposes:

  • Ad delivery
  • Tracking
  • Behavioral analytics through analytics SDKs
  • Persistent storage of personal data on developer-operated servers

2. Purposes of Use

We use the information handled in the App for the following purposes:

  • To allow users to create, edit, save, and view materials
  • To retain settings such as practice order, timers, and start positions
  • To save practice logs and notes so that they can be reviewed later
  • To sync material structures and practice logs across multiple devices when the Pro plan is used
  • To display metadata such as titles and durations of YouTube videos and playlists

3. Storage Locations

3.1 Local Storage

Including on the Free plan, material data created in the App and imported files may be stored in the App's local storage area on the device.

3.2 iCloud / CloudKit / iCloud Drive

When using the sync feature on the Pro plan, the App uses Apple's iCloud, CloudKit, and iCloud Drive to sync or store the following information:

  • Material structures
  • Practice logs
  • Material files that users choose to save as sync targets

These data are associated with the user's own Apple account and are managed through Apple's systems.

4. Access to Photo Library and Files

The App requests access to the Photo Library or files only at the following times:

  • When the user chooses to add images or videos as materials
  • When the user chooses to import PDF, image, video, or audio files

The App does not automatically obtain photos or files without the user's explicit action.

5. Use of YouTube API Services

The App uses URLs entered by users and may use YouTube API Services in order to handle YouTube videos or playlists as materials.

5.1 Embedded Playback

YouTube playback is provided through an embedded player.
The App does not download, extract, or background-play YouTube videos or audio.

5.2 Metadata Retrieval

To obtain metadata such as video titles, playlist names, and durations, the App may use a proxy service operated by us as well as Google's YouTube Data API.

During this process, service providers involved in the communications, such as Cloudflare and Google, may process IP addresses and other communication-related information in accordance with their respective privacy policies.

The App does not obtain users' YouTube login information or Google account credentials.

5.3 Google's Policies and Settings

In connection with the use of YouTube API Services, Google may handle information. For details, please refer to the following:

  • Google Privacy Policy: [https://policies.google.com/privacy](https://policies.google.com/privacy)
  • Google Security Settings: [https://security.google.com/settings/security/permissions](https://security.google.com/settings/security/permissions)

At this time, the App does not require Google Account sign-in or OAuth authorization and does not retain authentication tokens linked to Google Accounts. If such functionality is added in the future, this policy will be updated.

6. Provision to Third Parties

Except where required by law, we do not sell or provide user information to third parties.

However, the following external services may be involved in providing the App's functionality:

  • Apple (iCloud, CloudKit, iCloud Drive)
  • Google (YouTube embedded playback, YouTube Data API)
  • Cloudflare (proxy for retrieving YouTube metadata)

7. Data Retention and Deletion

Users can delete materials and logs within the App.
Deleted data will be removed in sequence from the device and any sync destination.

However, it may take some time for changes to be reflected on external services such as iCloud.

Users can also delete related information stored in the App by removing YouTube URLs. Permissions for Photo Library access can be changed in device settings as needed.

8. Children's Privacy

The App is not designed primarily for children.

9. Security

We strive to take reasonable security measures to protect the information handled in the App.
Local files are stored inside the App sandbox.
Data related to iCloud is processed in accordance with Apple's systems.

10. Changes to This Policy

We may revise this policy as necessary.
If any important changes are made, we will provide notice on the public page or within the App.

11. Contact

For inquiries regarding this policy, please contact: